Musnad Abu Ya'la al-Mawsili 12:1

Harun ibn Ma'ruf narrated to us, Bah ibn Wahb narrated to us, he said: And Yazid ibn 'Iyad informed me, from 'Imran ibn Abi Anas, from Abu al-Qasim Miqsam, the freed slave of Banu Rabi'ah, from al-Harith, who said: I prayed in the mosque of Banu Ghifar. When I sat, I began to supplicate and point with one finger. Khaffaf ibn Ima' al-Ghifari entered upon me while I was like that, and he said: "What do you intend by this, when you point with one finger?" I said: "I am supplicating to Allah and asking Him." He said: "How excellent is what you have done. Indeed, the Messenger of Allah (peace be upon him) used to do that. The polytheists said: 'He is only bewitching with it.' The polytheists lied; it is only sincerity."