Musnad Ahmad 788:66

Hashim ibn al-Qasim narrated to us, Shu'bah narrated to us, from Ghalib al-Tammar, who said: I heard Masruq ibn Aws—or Aws ibn Masruq—a man from Banu Yarbu', narrating that he heard Abu Musa al-Ash'ari narrating from the Prophet, peace and blessings of Allah be upon him, that he said: "The fingers are equal." I said to Ghalib: "Ten for each?" He said: "Yes."