Sayyiduna Jarir (may Allah be pleased with him) said: "I pledged allegiance to the Messenger of Allah (peace and blessings be upon him) on establishing the prayer, paying the zakah, and sincere goodwill towards every Muslim." And I am sincere in my goodwill towards you.
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2455