Musnad Ahmad 1060:41

Yahya narrated to us, 'Amr ibn 'Uthman narrated to us, he said: I heard Musa ibn Talhah, that Abu Ayyub informed him that a Bedouin confronted the Prophet, may Allah bless him and grant him peace, while he was on a journey. He took hold of the noseband of his she-camel, or the rein of his she-camel, and said: "O Messenger of Allah," or "O Muhammad, inform me of that which will bring me closer to Paradise and distance me from the Fire." He said: "You shall worship Allah and not associate anything with Him, and you shall establish the prayer, and you shall give the zakat, and you shall uphold the ties of kinship."