LIGHTNING, BENEDICTION ON:
The Mishnah (Ber. ix. 2) prescribes, "At the sight of shooting stars or of lightning, and at hearing earthquakes, thunder, and storms, the benediction 'Blessed be He whose power and might fill the world' should be recited. At the sight of great mountains, seas, and deserts one recites the benediction 'Blessed be He who hath made the work of Creation.'" The suggestion was made at the Babylonian school that the latter benediction is in place also on the occasions previously mentioned; and this was accepted by both Abbaye and Raba, who declared that both benedictions should be recited (Ber. 59a). However, Isaac Alfasi and Maimonides ("Yad," Berakot, x. 14) understand the Talmudic passage to mean that either benediction may be recited on the occasion of lightning and the other phenomena mentioned.
This view is accepted also by Asheri and his son Jacob (Ṭur Oraḥ Ḥayyim, 227); and by Joseph Caro (Shulḥan 'Aruk, Oraḥ Ḥayyim, 227, 1). General custom, however, decided that while for thunder the former benediction, expressive of God's might, should be recited, the benediction for lightning should be, "Blessed be He who hath made the work of Creation" (see "Ṭure Zahab" and "Be'er Heṭeb" to Shulḥan 'Aruk, Oraḥ Ḥayyim, l.c.). Accordingly, the ordinary prayer-books have this arrangement as a fixed rule.