In Tarif Khalidi’s new translation of the “Muslim gospel,” he provides 303 sayings and stories about Jesus in the Muslim tradition. I’m finding them fascinating. I’ll comment on a few to give us a taste of how Muslims appropriated Jesus into their own faith.
#2: Jesus said, “Blessed is he who guards his tongue, whose house is sufficient for his needs, and who weeps for his sins.” This saying, attributed to the bedrock of the Muslim Jesus tradition by ‘Abdallah ibn al-Murabak (c. 797 AD), appropriates Jesus into the ascetic tradition. At this time, the wandering teachers and preachers were contending against the encroaching luxury and power-hungering of established authorities. Control of the tongue, a lack of concern with acquiring more and more, and consciousness of sins marked the ascetic concern.

#4: “If it is a day of fasting for one of you, let him anoint his head and beard and wipe his lips so that people will not know that he is fasting. If he gives with the right hand, let him hide this from his left hand. If he prays, let him pull down the door curtain, for God apportions praise as He apportions livelihood.”
Again from ‘Abdallah ibn al-Murabak; same date. This text is clearly an adaptation of Matthew 6:1-18, in a different order. Instead of alms, prayer, fasting, this text has fasting, alms, and prayer. And two items are added: “pull down the door curtain” is perhaps a Muslim custom for prayer (anyone know?) and “as He apportions livelihood” is Deuteronomic: one gets in this world what one deserves. Khalidi makes a mistake in his commentary, suggesting that the Matthean text is addressed to Pharisees while the Muslim text is for “all hypocrites.” The Matthean text is also only addressed to the hypocrites. He joins the normal custom of equating hypocrites with Pharisees, and Pharisees with hypocrites.
In #6 we see a very common expression: Jesus is called “the son of Mary” and this text has to do with Jesus’ lack of knowledge of the future (a concern to show that Jesus was not divine). This text derives, ultimately, from the Christian perception of Jesus for Mark 13:34 has the same notion: that Jesus’ knowledge of the future is limited.
And #7 teaches that one should not take wages from those whom you teach and it also explains two characteristics of ignorance: laughter without cause for wonder and a “morning nap without wakefulness.” Khalidi explains the last comment to be about the discipline of praying through the entire night.