Musnad Ahmad 907:45

Yahya ibn Adam narrated to us, Israel narrated to us, from Simak ibn Harb, from Jabir ibn Samurah, who said: "The mu'adhdhin of the Messenger of Allah (may Allah bless him and grant him peace) would call the adhan, then he would wait. He would not perform the iqamah until, when he saw the Messenger of Allah (may Allah bless him and grant him peace) had come out, he would perform the iqamah when he saw him."