Even on the Sabbath, he labored for the sheep which he found fallen into the pit. (Gospel of Truth, saying #33)
For anyone not used to that way of looking at Scripture: That takes Jesus' teaching about how a shepherd will rescue a sheep from a pit on the Sabbath, and applies that to the Sabbath between Good Friday and Easter when Jesus was in the "pit" of death to rescue the lost sheep.
I think the "Gospel of Truth", which contains that saying, is misclassified; it's not a gospel of Jesus in the sense that we typically mean the word "gospel". It doesn't try to present a biography of his life. It doesn't try to record his teachings. It's more of an early commentary on how to understand Jesus' life and teachings, written somewhere around 160 A.D. (give or take a couple of decades). It was one of the earlier writings considered to be heretical; if you read it, you'll probably see why. Some of its teachings are a little bit off-base if we consider the apostles' information about Jesus as the best information about Jesus, and if we consider Judaism to be the right background for understanding Jesus' life and teachings. But it's reassuring in this much: even in Christian groups that have some questionable views, they may have decent views on other things, even on important things.
So I figure if St Paul can quote a non-Scriptural poet in one of his sermons, perhaps a lowly blogger could be forgiven for quoting a document with some known problems -- in a part that I think it got just right. Some things are a little too good to ignore, even if the surrounding material isn't necessarily the same quality. (Jesus also mentions -- referring to teachers who mislead -- that if the blind lead the blind, both will fall into the pit. That is another pit that the Good Shepherd saves us from.)
Thanks be to God that Jesus is the good shepherd, who went even on the Sabbath to rescue the sheep from the pit.