From Sahih Bukhari (Hadith 3693):
Narrated Abu Musa:While I was with the Prophet (ﷺ) in one of the gardens of Medina, a man came and asked me to open the gate. The Prophet (ﷺ) said to me, "Open the gate for him and give him the glad tidings that he will enter Paradise." I opened (the gate) for him, and behold! It was Abu Bakr. I informed him of the glad tidings the Prophet (ﷺ) had said, and he praised Allah. Then another man came and asked me to open the gate. The Prophet (ﷺ) said to me "Open (the gate) and give him the glad tidings of entering Paradise." I opened (the gate) for him, and behold! It was `Umar. I informed him of what the Prophet (ﷺ) had said, and he praised Allah. Then another man came and asked me to open the gate. The Prophet (ﷺ) said to me. "Open (the gate) for him and inform him of the glad tidings, of entering Paradise with a calamity which will befall him. " Behold ! It was `Uthman, I informed him of what Allah's Messenger (ﷺ) had said. He praised Allah and said, "I seek Allah's Aid
Reference: Bukhari 3693