Musnad Ahmad 907:3

'Abd al-Razzaq narrated to us, Isra'il informed us, he said: Simak informed me that he heard Jabir ibn Samurah saying: "The mu'adhdhin of the Messenger of Allah, may Allah bless him and grant him peace, would give the adhan, then he would wait. He would not perform the iqamah until, when he saw the Prophet of Allah, may Allah bless him and grant him peace, had come out, he would perform the iqamah for the prayer when he saw him."