Musannaf Ibn Abi Shayba 2:77

Abu Bakr narrated to us, he said: Harami ibn 'Umarah ibn Abi Hafsah narrated to us, from Shu'bah, from 'Abd al-Khaliq, from Hammad, that he saw no harm in a man giving the adhan while he is not in a state of wudu.