Musannaf Ibn Abi Shayba 2:122

Abu Bakr narrated to us, he said: Hatim ibn Isma'il narrated to us, from Ja'far, from his father and Muslim ibn Abi Maryam, that Ali ibn al-Husayn used to perform the adhan. When he reached "Hayya 'ala al-falah" (Come to success), he would say: "Hayya 'ala khayr al-'amal" (Come to the best of deeds). And he would say: "It is the first adhan."