Musnad Ahmad 32:264

Waki’ narrated to us, Shu’bah narrated to us, from Hamzah al-Dabbi, who said: I heard Anas ibn Malik saying: "When the Messenger of Allah (peace and blessings of Allah be upon him) would descend at a stopping place, he would not depart until he prayed Dhuhr." Muhammad ibn ‘Amr said to Anas: "O Abu Hamzah, even if it were at midday?" He said: "Even if it were at midday."