Augustine, Against Adversaries of the Law and Prophets 2.4.14 (it is now known that this saying comes from Thomas 52):
***The apostles asked the Lord: Has the advent already happened in the past?
And the Lord answered: You have dismissed the living one who is before your eyes and talk idly of the dead.***
Here is the saying from the Gospel of Thomas 52:
***His disciples said to him: Twenty-four prophets spoke in Israel, and they all spoke of you. He said to them: You have abandoned the living one before your eyes, and spoken about the dead. ***
Another saying found in Thomas which is quoted by the Church Fathers (already mentioned by another poster) is the following:
Origen, On Jeremiah, Latin homily 20.3:
He that is near me is near the fire.
He that is far from me is far from the kingdom
Gospel of Thomas saying 82
Jesus said: He who is near to me is near the fire, and he who is far from me is far from the kingdom.
Clement of Alexandria, Stromata, V, 10, 64:
***“For not grudgingly, he saith, did the Lord declare in a certain gospel: My mystery is for me and for the sons of my house.” ***
Gospel of Thomas 62:
I tell my mysteries to those who are worthy of my mysteries
There are many other such agrapha quoted by the Church Fathers which crop up in Thomas. We can only conclude that the Church Fathers either had a copy of the Gospel of Thomas, or one of the sources upon which it was based.