Is this a Masnun du’a to recite when it rains?
اللهم صيبا هنيئا
Allahumma sayyiban hani-an
O Allah! [Make] this a beneficial rain
Yes this is a du’a that Nabi (sallallahu ‘alayhi wa sallam) would recite when it would rain. Imam Abu Dawud, Imam Ibn Majah, Imam Ahmad (rahimahumullah) and other Muhaddithun have recorded the du’a.
(Sunan Abi Dawud, Hadith: 5058, Sunan Ibn Majah, Hadith: 3890, Musnad Ahmad, vol. 6 pg. 119. Also see here)
In Sunan Ibn Majah and some versions of Musnad Ahmad, the du’a is recorded with the following words:
اللهم اجعله صيبا هنيئا
Allahummaj-‘alhu sayyiban hani-an
O Allah! make this a beneficial rain
And Allah Ta’ala Knows best.
Answered by: Moulana Suhail Motala
Approved by: Moulana Muhammad Abasoomar