It wasnarrated from Abu Hurairah that the Messenger of Allah (ﷺ)said:
"When anyone of you enters the mosque, let him not sit downuntilhe performs two Rak'ah." (FR)
English reference (FR): Vol. 1, Book 5, Hadith 1012 (FR)
Arabic reference (FR): Book 5, Hadith 1065 (FR)