Musnad Ahmad 30:1564

Sulayman narrated to us, Isma'il narrated to us, Abu Suhayl Nafi' ibn Malik ibn Abi 'Amir informed me, from his father, from Abu Hurayrah, that the Prophet, peace and blessings of Allah be upon him, said: "The signs of the hypocrite are three: when he speaks, he lies; when he promises, he breaks it; and when he is entrusted, he betrays."