Musnad Ahmad 937:15

Husayn narrated to us, Yazid—meaning Ibn ‘Ata’—narrated to us, from Yazid—meaning Ibn Abi Ziyad—from Mujahid, from a man, from Abu Dharr, who said: The Messenger of Allah (may Allah bless him and grant him peace) came out to us and said: "Do you know which deeds are most beloved to Allah?" One person said: "Prayer and Zakat." Another said: "Jihad." He said: "Indeed, the most beloved of deeds to Allah is love for the sake of Allah, and hatred for the sake of Allah."