The Holy Prophet (s.a.w.a.) informed: Indeed Allah ordered me to love four people. He (s.a.w.a.) was asked: O Prophet of Allah! Who are they? The Prophet (s.a.w.a.) replied: Ali is one of them. I was also ordered to love Salman, Abu Zarr and Miqdad. I was told that Allah also loves them.
Al-Khesaal chap 4 trad 126