A good example of that would be within logion 21, which exemplifies the insertion of cleanly composed canonical pieces into badly written material with no parallels (some typically "Thomassan"), resulting into a bizarre and confusing assemblage (parallels in italics):
CoGTh 21: "Mary said to Jesus, "Whom are Your disciples like?"
He said, "They are like children who have settled in a field which is not theirs. When the owners of the field come, they will say, 'Let us have back our field.' They (will) undress in their presence in order to let them have back their field and give it back to them.
[how strange and badly written is the last sentence, with an useless repeat! And no apparent connection with what follows!]
` Therefore I say to you, if the owner of a house knows that the thief is coming, he will begin his vigil before he comes and will not let him into his house of his domain to carry away his goods. You, then, be on your guard against the world. Arm yourselves with great strength lest the robbers [who would take your faith away!] find a way to come to you, for the difficulty which you expect will (surely) materialize.
Let there be among you a man of understanding.
[Jesus is answering Mary, a woman!]
` When the grain ripened, he came quickly with his sickle in his hand and reaped it.
[who is "he"? No obvious relation to what is preceding. And the whole sentence is begging for a context]
` Whoever has ears to hear, let him hear".
[why would Jesus say that to Mary then?]"
Parallels in the synoptic gospels:
Mt24:43 "But know this, that if the master of the house had known what hour the thief would come, he would have watched and not allowed his house to be broken into."
Mk4:26-29 (the parable of the growing seed) "And He said, "The kingdom of God is as if a man should scatter seed on the ground, and should sleep by night and rise by day, and the seed should sprout and grow, he himself does not know how. For the earth yields crops by itself: first the blade, then the head, after that the full grain in the head. But when the grain ripens, immediately he puts in the sickle, because the harvest has come
[this last sentence was probably isolated in Logion 21 in order to remove any eschatological content, very obvious within the context of the Markan parable].""
Mk4:9 "And He said to them, "He who has ears to hear, let him hear!""