#2 Greeting while praying

a person holding their hands up in front of a window
shallow focus photography of person's left hand outside

Book of Actions while Praying

(15) Chapter: One should not return greetings during the Salat

Hadith 1216

Narrated `Abdullah:

I used to greet the Prophet (صلى الله عليه وسلم) while he was in prayer and he would return my greeting, but when we returned (from Ethiopia) I greeted the Prophet (while he was praying) but he did not return the greeting, and (after finishing the prayer) he said, “In the prayer one is occupied (with a more serious matter).”