Shaking Hands after the Jumu'ah and Eid Salaahs

Q: Salaah-183: Is there any substantiation for congratulating each other by shaking hands when the moon is sighted for joyous occasions, on Fridays and especially after the Eid salaah?

Answer: Shaking hands in itself is a Sunnah practice but there is nothing to substantiate the act of shaking hands to congratulate each other upon sighting the moon or after the Jumu'ah and Eid salaahs. It is for this reason that the Fuqahaa classify this act as Makrooh and an act of Bid'ah.

Fatawa Rahimiyyah vol.2