It was narrated that Jabir said:“The Prophet (ﷺ) sent me on an errand, then I caught up with him while he was performing prayer, and I greeted him. He gestured to me, then when he finished, he called me and said: ‘You greeted me before, but I was performing prayer.’”
Hadith No. 1018
Sunan Ibn Majah
Gradings:
Al-Albani:
Sahih
Muhammad Fouad Abd al-Baqi:
Sahih
Shuaib Al Arnaut:
Sahih
Zubair Ali Zai:
Sahih Muslim