Musnad Ahmad 2:73

Hashim narrated to us, he said: Al-Zuhri claimed, from Ubayd Allah ibn Abd Allah ibn Utbah ibn Mas'ud, from Ibn Abbas, from Umar, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Do not exaggerate in praising me as the Christians exaggerated in praising the son of Maryam, for I am only a servant of Allah and His Messenger."