Companions come and go, but to find some one truly worthy of granting the title “friend” is a rare thing indeed. We can spend our entire life and not have even one lasting relationship let alone someone we would call a dear and intimate friend. So when the Prophet (saws) expresses and considers one to be such a person, a khalil, then they must truly be a person of unique character.
Chapter 5: The saying of the Prophet (saws) “If! were to take a Khalil…”
AbU Sa’id said that Ibn ‘Abbas (raa) narrated, the Prophet (saws) said, “If I were to take a Khalil, I would have taken Abu Bakr (raa), but he is my brother and my companion (in Islam).”