Qur'an 48:18

۞ لَّقَدْ رَضِىَ ٱللَّهُ عَنِ ٱلْمُؤْمِنِينَ إِذْ يُبَايِعُونَكَ تَحْتَ ٱلشَّجَرَةِ فَعَلِمَ مَا فِى قُلُوبِهِمْ فَأَنزَلَ ٱلسَّكِينَةَ عَلَيْهِمْ وَأَثَـٰبَهُمْ فَتْحًا قَرِيبًا

Allah was well pleased with the believers when they swore allegiance unto thee beneath the tree, and He knew what was in their hearts, and He sent down peace of reassurance on them, and hath rewarded them with a near victory;