He asked the Prophet ﷺ about the best form of faith.The Prophet ﷺ replied, "That you love for the sake of Allah, hate for the sake of Allah, and keep your tongue engaged in the remembrance of Allah."He asked, "What else, Messenger of Allah?"The Prophet ﷺ said, "And that you love for people what you love for yourself, and hate for them what you hate for yourself."
حدثنا عبد الله حدثني أبي حدثنا يحيى بن غيلان حدثنا رشدين عن زبان عن سهل عن أبيه
أنه سأل النبي ﷺ عن أفضل الإيمان قال أن تحب لله وتبغض لله وتعمل لسانك في ذكر الله قال وماذا يا رسول الله قال وأن تحب للناس ما تحب لنفسك وتكره لهم ما تكره لنفسك
Its isnad is hasan, because of Rushdin bin Saad and Ziyadah, concerning whom there is some discussion, though people praised him and praised his governorship over Egypt. Sahl bin Muaz is the son of Anas, he is trustworthy, and his father was a companion. Munziri mentioned the hadith at 4/23 and attributed it to Ahmad.