لِّيُدْخِلَ الْمُؤْمِنِينَ وَالْمُؤْمِنَاتِ جَنَّاتٍ تَجْرِي مِن تَحْتِهَا الْأَنْهَارُ خَالِدِينَ فِيهَا وَيُكَفِّرَ عَنْهُمْ سَيِّئَاتِهِمْ ۚ وَكَانَ ذَٰلِكَ عِندَ اللَّهِ فَوْزًا عَظِيمًا
“So He may admit believing men and women into Gardens under which rivers flow —to stay there forever— and absolve them of their sins. And that is a supreme achievement in the Sight of Allah.”
This ayah is part of Surah al-Fath, revealed -- as this event's own significance note states -- "concerning this incident" (Q48:1), the Treaty of Hudaybiyyah.