The משנה at the beginning of פרק ה of מסכת סנהדרין relates that בית דין asks the עדים – the witnesses – seven questions referred to as דרישות וחקירות. These are questions which establish the exact time and location of the alleged acts about which the עדים are testifying. The גמרא says that additional basic questions about the case must be asked of the עדים, such as, in the case of עבודה זרה (idolatry) את מי עבד ובמה עבד - Which idol did the accused serve and how did he serve it? רש"י explains that these additional, required questions are actually classified as בדיקות – a different class of questions asked by בית דין – as דרישות וחקירות only include questions of time and place. The יד רמ"ה categorizes these questions as a special type of בדיקות, noting that if the עדים fail to answer them, their testimony is invalid.
However, the רמב"ם takes a different approach. In the first פרק of הלכות עדות, the רמב"ם writes that all of the questions which are material to the case, such as – in the case of חילול שבת – which מלאכה was performed by the accused, how did he perform it, and so on, are classified as דרישות וחקירות. Although everyone agrees that the seven questions of time and place are דרישות וחקירות, as they are needed to make the עדות | עדות שאתה יכול להזימה – testimony which can be refuted by proving that the witnesses were not present – the רמב"ם goes further and includes all material questions in the category of דרישות וחקירות. Let's try to understand what the רמב"ם's theory is.
The יד רמ"ה writes that בית דין only asks the עדים the seven דרישות וחקירות of time and place if they failed to state the time and place in their initial testimony. However, if the עדים testify that the accused committed a murder in a certain year, or that the crime occurred yesterday, בית דין can skip any questions of time and place which are now redundant. The רמב"ם disagrees and requires that the seven questions of time and place ALWAYS be asked. It is not likely that the reason that the רמב"ם requires that the seven questions always be asked is because he holds that בית דין needs to challenge or do extra verification of the truthfulness of the עדים, whereas the רמ"ה disagrees, as ALL opinions must submit to the rule of מסיעין את העדים – that בית דין must try to disorient and distract the עדים in order to verify their truthfulness. The רמב"ם's position, that the seven questions must always be asked even if they have become redundant, therefore seems to hinge on a different reason.
Furthermore, in פרק י"ב of הלכות סנהדרין, the רמב"ם writes that as soon as the עדים provide a minimal, one-sentence summary of the charges, בית דין immediately asks them if the accused was warned before committing the alleged crime and if the עדים recognize the victim; and the רמב"ם continues that the עדים immediately undergo איום – stern warning about the sin of testifying falsely, after which they are asked the balance of the דרישות וחקירות about the time and place and all material facts of the alleged crime. Rather than first allowing the עדים to present the case in full, the רמב"ם explains in this halacha as well as at the end of פרק א' of הלכות עדות that they are immediately put through דרישות וחקירות, as he apparently maintains that through the דרישות וחקירות is the עדות – the testimony – created.
In other words, the רמב"ם's opinion is that דרישות וחקירות are not merely questions of time and location for the purposes of potential הזמה (the ability to challenge the עדים’s presence at the alleged incident). Rather, the רמב"ם establishes that the very testimony is created and given legal significance only and precisely because it is created via the process of דרישה וחקירה. This is why the עדים cannot tell their whole story and THEN undergo דרישות וחקירות, but – on the contrary – the עדות must be drawn from them and created from the start via דרישה וחקירה; the entire עדות must arise through דרישות וחקירות. This also explains why the רמב"ם holds that all seven questions of time and place must be asked even if they seem redundant, as the תורה established the דרישות וחקירות as the halachic formula for creating עדות; if the formula is not used, the עדות lacks a שם – a legal status – of עדות.
We can now understand the רמב"ם's statement in פרק א' of הלכות עדות inה' הלכה that הדרישות והחקירות הן הדברים שהן עיקר העדות ובהן יתחייב או יפטר, והן כוונת המעשה שעשה, וכיוון הזמן וכיוון המקום – The דרישות וחקירות are the principal things which constitute the essence of the עדות and through them is the accused found to be guilty or innocent; they determine the alleged action, its time and place. In making this statement, the רמב"ם is not just summarizing or making an unnecessary comment. Rather, he is establishing an important halachic principle: The דרישות וחקירות create the עדות, and without them, the witnesses' statements are mere narrative, without legal status.
Based on this, we can understand why the רמב"ם clearly maintains in הלכה ד' of this פרק in הלכות עדות that the rule of מסיעין את העדים is actually part of the דרישה וחקירה process, for דרישות וחקירות serve as בירור – establishing and clarifying the עדות, rather than merely as a facilitator for the ability to do הזמה.
We can now also understand some additional points in the רמב"ם's view of דרישות וחקירות and עדות. In הלכות עדות, פרק ב' הלכה א', the רמב"ם writes that a contradiction between עדים in דרישות וחקירות or בדיקות – referred to as הכחשה – invalidates the עדות based on the גזירת הכתוב of נכון הדבר – the Scriptural rule that the עדות cannot be incorrect. However, the רמב"ם fails to apply the פסול – the invalidation – of נכון to the case of an עד answering "I don't know" to questions of דרישות וחקירות, which likewise invalidates the עדות. The reason for this apparent omission by the רמב"ם is precisely because he holds that failure to answer the questions of the דרישות וחקירות means that there is no עדות at all. Therefore, the rule of נכון is not applicable, as the דרישות וחקירות were in this case not completed – because the witness did not answer the questions – he just said, “I don't know.” The עדות is invalid by definition, without the גזירת הכתוב of נכון הדבר, as the עדות was not created by completing the process of דרישה וחקירה, and hence it is by definition not considered to be עדות.
An important נפקא מינה – a difference – between the opinions of רש"י and the יד רמ"ה versus the רמב"ם is in the case of עדים retracting their testimony. There is a rule of כיון שהגיד, שוב אינו חוזר ומגיד – Once an עד relates his testimony and has undergone דרישה וחקירה, he cannot retract. Several ראשונים learn that the reason that retraction is not possible after the דרישות וחקירות is that דרישות וחקירות represent the conclusion of קבלת העדות – בית דין's acceptance of the testimony. These ראשונים indicate that the rule of כיון שהגיד, שוב אינו חוזר ומגיד is a limitation on the positive right to retract עדות, such that one may retract until the דרישות וחקירות occur. However, according to our understanding in the רמב"ם, the rule of כיון שהגיד is inverted – as until the דרישות וחקירות are done, there is absolutely no עדות, and THAT is why the עדים can retract their words until the דרישות וחקירות are done, as their words do not have the status of עדות until that point. This is probably why the רמב"ם phrases the concept of כיון שהגיד in the negative when he introduces the concept in פרק ג' of הלכות עדות, as according to the רמב"ם, there is no such thing as עדות which can be retracted until the דרישות וחקירות; rather, the עדים's statements prior to דרישות וחקירות are not עדות at all.
Based on our understanding in the רמב"ם, we can also answer a קושיא of the לחם משנה. In פרק ב', הלכה ג' of הלכות עדות, the רמב"ם writes that if there are more than two עדים in a group, and two of them answer the דרישות וחקירות accurately but the rest reply, “We don't know” to the דרישות וחקירות, the עדות of the two witnesses who answered properly is kosher. The לחם משנה asks how this can be, as the רמב"ם paskens like רבי עקיבא and רבי שמעון that if any עדים in the group are invalid, the entire group is deemed invalid, and that a כשר group of עדים requires that all in the group be valid so that הזמה can be done, and the גמרא on מ"א: equates the opinion of רבי עקיבא (who agrees with רבי שמעון) with the case of two עדים replying accurately to the דרישות וחקירות and the other עדים in the group saying, "We don't know." Although we cannot answer the apparent contradiction between the רמב"ם and the גמרא, we can surely understand the רמב"ם's differentiation. If any עדים in the group are found to be invalid or their עדות is disqualified, the entire group is declared invalid. However, if two עדים answer the דרישות וחקירות accurately and others reply, "We don't know", they do NOT invalidate the rest of the group, as the testimony of the עדים who answer, “We don't know” is really not עדות, as by saying “We don't know”, they have not completed the process of דרישה וחקירה, whose completion is required to create עדות, according to the רמב"ם.
In the first piece on הלכות עדות in חדושי רבינו חיים הלוי, רב חיים writes that the רמב"ן holds a שטר מאוחר – a postdated contract, signed by witnesses – to be invalid without the special תקנה – dispensation – in ל"ב: of מסכת סנהדרין that does away with דרישות וחקירות in דיני ממומות – monetary cases – כדי שלא תנעול דלת בפני לווין – in order not to discourage lending money. רב חיים explains that the רמב"ן holds that עדות in a שטר מאוחר is עדות מוכחשת, testimony with a contradiction, and that the שטר would therefore be invalid without the special .תקנה Since the עדים in a שטר מאוחר testify inaccurately about the real date of the שטר’s creation, their words about the date are עדות מוכחשת. רב חיים quotes from the בעל התרומות that the רמב"ן holds that after the תקנה, עדות מוכחשת in דיני ממומות is acceptable if דרישות וחקירות, which are no longer required, are nonetheless done. רב חיים demonstrates that the רמב"ם disagrees with the רמב"ן and holds that testimony about the date in a שטר מאוחר is not עדות מוכחשת, and that even after the תקנה of כדי שלא תנעול דלת בפני לווין, עדות מוכחשת would nonetheless invalidate in all cases.
It would seem that these two arguments of the רמב"ם and the רמב"ן can be explained based on our explanation in the רמב"ם regarding דרישות וחקירות and עדות. The רמב"ן holds like רש"י and the רמ"ה that דרישות וחקירות are done merely to make the עדות susceptible to הזמה. Therefore, they are a technical requirement that do not affect the heart of the case. Thus, the רמב"ן holds that a contradiction in דרישות וחקירות after the תקנה of כדי שלא תנעול דלת בפני לווין does not invalidate the עדות, as דרישות וחקירות are not material to the case itself. So, too, the רמב"ןholds that testimony in a שטר מאוחר is עדות מוכחשת, as there is a technical contradiction between the date attested to by the עדים and the actual date of the event. On the other hand, the רמב"ם maintains that even after the תקנה, contradiction in the דרישות וחקירות would invalidate in all cases, as such contradiction is not a mere technicality, for the דרישות וחקירות establish the entire testimony, and contradiction in the דרישות וחקירות would therefore invalidate it, as it would reflect a flaw in the heart of the testimony rather than a mere technical issue that can be overlooked. So, too, would the רמב"ם not disqualify a postdated שטר based on עדות מוכחשת, as since he holds that the דרישות וחקירות reflect the reality and entire scope of the event and situation – the עיקר העדות – rather than a technical detail, it is understood that in reality the discrepancy between the date reported by the witnesses in the שטר and the date that the שטר was created is not a real contradiction, for parties often agree for the indebtedness to be established in writing on a later date. Since the עדים in their דרישות וחקירות are testifying in reality to the date of legal indebtedness, their replies to the דרישות וחקירות are not invalidated as עדות מוכחשת, even though from a purely technical perspective they are inaccurate. The רמב"ן must rule that the witnesses' statement about the date is עדות מוכחשת, as technically the date is not accurate, and the technical function of דרישות וחקירות would otherwise be meaningless. The רמב"ם, who holds that the דרישות וחקירות actually establish the case and serve a broader function, accepts the עדות of the date in a שטר מאוחר, as it can testify to the date of indebtedness, which is part of the larger reality at hand.