Sahih al-Bukhari Book 62, Hadith 11
A woman came to the Prophet (ﷺ) who ordered her to return to him again. She said, "What if I came and
did not find you?" as if she wanted to say, "If I found you dead?" The Prophet (ﷺ) said, "If you should not
find me, go to Abu Bakr."
The people of Kufa sent a letter to Ibn Az-Zubair, asking about (the inheritance of) (paternal) grandfather. He replied that the right of the inheritance of (paternal) grandfather is the same as that of father if the father is dead) and added, "Allah's Messenger (ﷺ) said, ' If I were to take a Khalil from this nation, I would have taken him (i.e. Abu Bakr).
I saw Allah's Messenger (ﷺ) and there was none with him but five slaves, two women and Abu Bakr (i.e. those were the only converts to Islam then).