Musannaf Ibn Abi Shayba 3:631

Ibn Fudayl narrated to us, from Dawud ibn Abi Hind, from Abu al-Aliyah, who said: Ibn Abbas heard a man praying. When he sat to perform the tashahhud, he said, "Praise be to Allah, the greetings are for Allah." Ibn Abbas said, while rebuking him, "Praise be to Allah! When you sit, begin the tashahhud with 'the greetings are for Allah' (al-tahiyyatu lillah)."