The Talmud (Berakhot 59a) discusses reciting a berakhah on lightning. The Chayei Adam (63:7) maintains that this berakhah is only recited on lightning that comes with thunder. The Tzlach, however, reflects a different understanding in his commentary, interpreting the Talmud to be referring even to weaker lightning that does not come in association with thunder (apparently included those caused by the heat). R. Shmuel Wosner (Resp. Shevet HaLevi X, 48), however, disputes the Tzlach, noting that his proof is based on a textual formation not all rishonim agree to. He concludes that the practice is like the Chayei Adam, which is cited as well by the Mishnah Berurah, not to recite the berakhah on lightning not associated with thunder.