Halakhah к Ийова 37:4

There is, however, a parallel text in the Yerushalmi, the Palestinian Talmud, Berakhot 9:2. The Yerushalmi also records that the blessing oseh ma'aseh bereshit is pronounced upon seeing "the firmament in its purity." But, in the Yerushalmi's discussion, R. Huna explains that the blessing is recited "only in the rainy season after three days, as it is written, 'And now they did not see light that is bright in the skies but a wind passes and cleanses them'" (Job 37:4), i.e., the blessing is recited after incessant rain spanning a three-day period. R. Moshe Sofer, Teshuvot Hatam Sofer, Oraḥ Hayyim, no. 55, expresses bewilderment: Why is the blessing occasioned only by three days of rainfall? Hatam Sofer amends the text to read "after thirty days" but fails to explain why the blessing is recited only after a thirty-day period of rainfall.