Jami` at-Tirmidhi Book 49, Hadith 52
"Abu Bakr is our chief, and the best of us, and the most beloved of us to the Messenger of Allah (ﷺ)."
that the Messenger of Allah (ﷺ) said: "I free myself of the friendship of every Khalil, and if I were to take a Khalil then I would have taken Ibn Abi Quhafah as a Khalil. And indeed your companion is Allah's Khalil."
"I said to 'Aishah: 'Which of the Companions of the Prophet (ﷺ) were the most beloved to the Messenger of Allah (ﷺ)?' She said: 'Abu Bakr.' I said: 'Then who?' She said: ''Umar.' I said: "Then who?' She said: 'Then Abu 'Ubaidah bin Al-Jarrah.'" He said: "I said: 'Then who?''" He said: "Then she was silent."