The Apostle of Allah (ﷺ) owed me a debt; he paid me back and made an addition (of this). I entered the mosque and he (the Holy Prophet) said to me: Observe two rak'ahs of prayer.
Sahih Muslim Book 6, Hadith 86
← Previous Hadith I entered the mosque, when the Messenger of Allah (ﷺ) had been sitting among people, and I also sat down among them. Upon this the Messenger of Allah (ﷺ) said: What prevented you from offering two rak'ahs (of Nafl prayer) before sitting down? I said: Messenger of Allah, I saw you sitting and people sitting (around you and I, therefore, sat in your company). He (the Holy Prophet) then said: When anyone among you enters the mosque, he should not sit till he has observed two rak'ahs.

Sahih Muslim Book 6, Hadith 85 Next Hadith → The Messenger of Allah (ﷺ) bought a camel from me. When he came back to Medina, he ordered me to come to the mosque and observed two rak'ahs of prayer.

Sahih Muslim Book 6, Hadith 87