Al-Fath · 48:18

18. Verily, Allah was pleased with the believers when they were giving their oaths to you at Ḥudaybīyyah i.e. Bay‘at Al-Riḍwān under the tree. Allah knew of the faith, sincerity and honesty in their hearts and sent down tranquility on their hearts. And He rewarded them for it with a victory in the near future i.e. the victory over Khaybar, as consolation for them missing out on being able to enter Makkah.