Musnad Abu Ya'la al-Mawsili 129:48

Narrated to us Wahb, informed us Khalid, from Humayd, from Anas, that the Messenger of Allah (peace and blessings of Allah be upon him) said to a man from Banu al-Najjar: "O Uncle, accept Islam." He said: "I find myself averse to it." He said: "Even if you are averse to it, and you are compelled to it."