Ammar bin Yasir reported,

He greeted the Prophet ﷺ with the salam while he was praying, and the Prophet returned his greeting.

Azami 2647

Sahih

عن عمار بن ياسر

أنه سلم على النبي ﷺ وهو يصلي، فرد عليه.

الأعظمي 2647صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
Minor actions do not invalidate the prayer
Section
Returning the greeting by gesture during prayer
Numbering
Jami al-Kamil 2647 (2nd edition)
Azami 2647