Sayyiduna Ibn Umar (may Allah be pleased with them both) said: We were with the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) looked for Bilal (may Allah be pleased with him) to call the adhan for the people, but he could not be found. So the Messenger of Allah (peace and blessings be upon him) ordered a man, and he called the adhan in Bilal's place. Then after that (Bilal) wanted to call the iqamah, and the Messenger of Allah (peace and blessings be upon him) said: "The iqamah is called only by the one who called the adhan."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13533