Musnad Ahmad 39:4

'Affan narrated to us, Wuhayb narrated to us, Musa ibn 'Uqbah narrated to me, he said: I heard Abu Salamah narrating—and I do not know him to be narrating except from Nafi' ibn 'Abd al-Harith—that the Messenger of Allah (may Allah bless him and grant him peace) entered one of the gardens of Medina and sat on the edge of the well. Then Abu Bakr came seeking permission [to enter], so he said: "Give him permission and give him glad tidings of Paradise." Then 'Umar came seeking permission, so he said: "Give him permission and give him glad tidings of Paradise." Then 'Uthman came seeking permission, so he said: "Give him permission and give him glad tidings of Paradise, and he will encounter a trial."