Asalamu alakium dear shiekh Recently I have been seeing this alot on social media people replying with thuma ameen... or summa ameen and also I've heard people saying this after anything good happens is there any evidence for this saying in the sunnah of the prophet and is there any saheeh narrations for this saying jazakallahu khyran

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The word Ameen means, "O Allaah, respond (or answer our supplication)." If it is said after the supplication, there is no harm in that as this is its proper place. However, using it in other contexts is inappropriate and should not be done.

Adding the particle "thumma", which means "then", in this context is meaningless. The conjunction "thumma" in Arabic is used to indicate coordination with sequence. It should be noted that the proper pronunciation of the word is "thumma" and not "summa".

Allaah Knows best.