Musnad Ahmad 200:3

Yazid narrated to us, he said: Abu Malik al-Ashja‘i informed us, he said: My father narrated to me that he heard the Messenger of Allah, peace and blessings of Allah be upon him, saying when a man came to him and said: "How should I say, O Messenger of Allah, when I ask my Lord?" He said: "Say: 'O Allah, forgive me, have mercy on me, guide me, and provide for me.'" And he clenched his four fingers, excluding the thumb. "For these gather for you your worldly life and your Hereafter."