Sunan Abi Dawud 512

ʿUthman ibn Abi Shaybah narrated to us: Hammad ibn Khalid narrated to us: Muhammad ibn ʿAmr narrated to us, from Muhammad ibn ʿAbd Allah, from his uncle ʿAbd Allah ibn Zayd, who said: The Prophet (peace and blessings be upon him) considered various ways of calling people to prayer, but did not implement any of them. Then ʿAbd Allah ibn Zayd was shown the call to prayer in a dream. He went to the Prophet and told him, and he said: ‘Teach it to Bilal.’ He taught it to him, and Bilal called the prayer. ʿAbd Allah said: ‘I saw it, and I had wanted to do it.’ He replied: ‘Then you perform the iqamah.’