Observations regarding Jesus' sayings in the Qur'an, which I made while reading James White's new book, What Every Christian Needs to Know About the Qur'an:
- There are exactly 15 ayat in the Qur'an, spread out across 5 surat, that contain what are claimed to be sayings by Jesus (3:49-52, 5:112,114,116 19:30-33,36 and 43:63). This does not include verses which mention Jesus but do not include any sayings attributed to Him.
- Not a single one of the aforementioned sayings have any parallel in Jesus' actual teachings in the New Testament. In fact, some statements are directly opposed to them (eg. Surah 5:116 directly opposes what Jesus actually said in Matthew 11:27 and Luke 10:22).
- Only one of those sayings (comprising 4 ayat) has an identifiable historical setting (Surah 19:30-33). All of the other sayings of Jesus in the Qur'an do not have any setting in time and space (except Surah 5:116, which is supposed to be in the future and therefore has not actually been said yet).
- The saying in Surah 3:49 is taken directly from the apocryphal Infancy Gospel of Thomas (ch. 2).
For more information (including exegesis of the relevant verses and what various tafaasir and ahadith have to say about them), I would recommend getting the aforementioned book by Dr. White. The relevant chapter is chapter five.