Sending Salutations of Peace upon the Prophet is Lawful
Question :
If sending salutations of peace is a good innovation, then is it permissible to forbid the people from sending salutations of peace upon the noble Prophet?
Answer:
Sending blessings and salutations of peace upon our Messenger, and upon his brothers, the Prophets is not a good innovation, as the questioner says; in fact, they are both lawful, based upon sound evidences. Therefore, it is not permissible to forbid the people from doing so, unless it is done in a way which was not done during the time of the righteous Companions or the Tabi'in, such as the practice of saying it aloud after the Adhan, as if it were a part of the Adhan, or such as the gathering of people at specific times, expressly for the purpose of sending prayers and salutations upon the Prophet, since this has not been reported from our righteous ancestors. Performing them in this way is therefore the innovation which is detested and which has no basis (in the Sunnah). And may peace and blessings be upon our Prophet, Muhammad and upon his family and Companions.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 1 Pages 285-286
أرسلها على تطبيق الواتساب 
