(28) بَابُ مَا جَاءَ فِي التَّطَوُّعِ مَثْنَى مَثْنَى
Narrated Jabir bin `Abdullah:
While delivering a sermon, Allah's Messenger (ﷺ) said, "If anyone of you comes while the Imam is delivering the sermon or has come out for it, he should offer a two rak`at prayer."
Reference: Sahih al-Bukhari 1170
In-book reference: Book 19, Hadith 49
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 21, Hadith 267