Sahih Muslim 876
Abu Rifa'a reported:
I came to the Prophet (ﷺ) when he was delivering the sermon, and I said: Messenger of Allah, here is a stranger and he wants to learn about this religion and he does not know what this religion is. The Messenger of Allah (ﷺ) looked at me and left his sermon till he came to me, and he was given a chair and I thought that Its legs were made of iron. The Messenger of Allah (ﷺ) sat In it and he began to teach me what Allah had taught him. He then came (to the pulpit) for his sermon and completed it to the end.
وَحَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا سُلَيْمَانُ بْنُ الْمُغِيرَةِ، حَدَّثَنَا حُمَيْدُ بْنُ هِلاَلٍ، قَالَ قَالَ أَبُو رِفَاعَةَ انْتَهَيْتُ إِلَى النَّبِيِّ صلى الله عليه وسلم وَهُوَ يَخْطُبُ قَالَ فَقُلْتُ يَا رَسُولَ اللَّهِ رَجُلٌ غَرِيبٌ جَاءَ يَسْأَلُ عَنْ دِينِهِ لاَ يَدْرِي مَا دِينُهُ - قَالَ - فَأَقْبَلَ عَلَىَّ رَسُولُ اللَّهِ صلى الله عليه وسلم وَتَرَكَ خُطْبَتَهُ حَتَّى انْتَهَى إِلَىَّ فَأُتِيَ بِكُرْسِيٍّ حَسِبْتُ قَوَائِمَهُ حَدِيدًا - قَالَ - فَقَعَدَ عَلَيْهِ رَسُولُ اللَّهِ صلى الله عليه وسلم وَجَعَلَ يُعَلِّمُنِي مِمَّا عَلَّمَهُ اللَّهُ ثُمَّ أَتَى خُطْبَتَهُ فَأَتَمَّ آخِرَهَا ‏.‏