Jami` at-Tirmidhi Book 49, Hadith 65
that the Messenger of Allah (ﷺ) departed one day and entered the Masjid, along with Abu Bakr and 'Umar. One was on his right and the other was on his left, and he was holding their hands, and he said: "This is how we will be resurrected on the Day of Judgement.'"
that the Messenger of Allah (ﷺ) used to go out to his Companions from The Muhajirin and the Ansar while they were sitting, and Abu Bakr and 'Umar would be with them. No one would lift their sight towards him except Abu Bakr and 'Umar, because they used to look at him, and he would look at them, and they would smile at him, and he would smile at them.
that the Messenger of Allah (ﷺ) said to Abu Bakr: "You are my companion at the Hawd, and my companion in the cave."