قال الله تعالى: إِنَّ اللہَ وَمَلَائِكَتَهُ يُصَلُّونَ عَلَى النَّبِيِّ يَا أَيُّهَا الَّذِينَ آمَنُوا صَلُّوا عَلَيْهِ وَسَلِّمُوا تَسْلِيماً
Undoubtedly, Allah and His angels send blessings on the prophet the Communicator of unseen news, O you who believe! Send upon him blessings and salute him fully well in abundance.
Surah Al Ahzab -33, Aayat 56
If recited once, a person will gain as much deeds (sawab) as if 1000 angles write deeds for 70 days or if 70 angles write deeds for 1000 days, still won’t be able to write them all. (Hazrath Abdul Wahab Sherani – MIZAN)