Mishkat al-Masabih #44

He also said that he asked the Prophet what was the most excellent aspect of faith, and received the reply, “That you should love for God’s sake, hate for God’s sake, and employ your tongue in making mention of God.” “What more, messenger of God?” he asked and was told, “That you should like other people to have what you like yourself, and dislike that they should have what you dislike yourself.” Ahmad transmitted it.