Is it permissible to pray and send peace upon anyone other than the Prophet (peace and blessings be upon him)?

Question:
Honorable Shaykh, may Allah grant you success, he says: Is it permissible to say to someone other than the Messenger (peace and blessings be upon him), "So-and-so, peace and blessings be upon him"?

Answer:
Yes, it is permissible if it is not adopted as a permanent slogan. I mean, sometimes there is no harm, but if it is adopted as a slogan, like the Rafidah do with 'Ali and the People of the House, where they single them out and say "peace be upon him" or "peace and blessings be upon him," that is a slogan and it is not permissible.