As per Quran;|
"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"
Malik narrates that Muhammad (PBUH) said:
"He who reads a single Durood upon me, Almighty Allah blesses him ten times, ten
of his sins are forgiven, and he is increased ten times in stages (internally)"