وَإِنْ أَحَدٌ مِّنَ الْمُشْرِكِينَ اسْتَجَارَكَ فَأَجِرْهُ حَتَّىٰ يَسْمَعَ كَلَامَ اللَّهِ ثُمَّ أَبْلِغْهُ مَأْمَنَهُ ۚ ذَٰلِكَ بِأَنَّهُمْ قَوْمٌ لَّا يَعْلَمُونَ
“And if any one of the polytheists seeks your protection, then grant him protection so that he may hear the words of Allah. Then deliver him to his place of safety. That is because they are a people who do not know.”
This ayah is part of the opening of Surat al-Tawba, revealed -- as this event's own description states -- within hours of Abu Bakr RA's Hajj delegation departing Madinah, and proclaimed by Ali ibn Abi Talib RA during that Hajj.