From James White’s
The King James Only Controversy, “Part Two – The Textual data”, pages 252, 253.
Luke 11:2-4: THE LORD’S PRAYER
Luke’s version of the Lord’s Prayer is highly abbreviated in its original form. Scribes sensed a problem and made a number of attempts at harmonization. The influence of Matthew’s version is seen throughout the later Greek manuscripts and, hence, in the TR’s reading of Luke’s account. Entire phrases are imported into Luke, resulting in a much longer version in the King James Version. The comparison between the KJV and a modern translation such as the NIV is often disconcerting to someone who is not familiar with the reasons for the differences.
KJV
And he said unto them, When ye pray, say, Our Father which art in heaven, Hallowed be thy name. Thy kingdom come. Thy will be done, as in heaven, so in earth. Give us this day our daily bread. And forgive us our sins; for we also forgive every one that is indebted to us. And lead us not into temptation; but deliver us from evil.
NIV
He said to them, “When you pray, say, ‘Father, hallowed be your name, your kingdom come. Give us each day our daily bread. Forgive us our sins, for we also forgive everyone who sins against us. And lead us not into temptation.’ ”
Each of the [bold] phrases is found in Matthew’s version of the Lord’s Prayer. These additions were made quite early on, demonstrating that this prayer had an important part in the liturgy of the ancient church. As was the case with the longer addition in Matthew 6:13, so too we find a number of variants here as well. Most are to be traced directly to Matthew 6. One of the more interesting, however, that does not come from Matthew is the addition on the part of a few later minuscules of the phrase “Let Your Holy Spirit come upon us and cleanse us.” This phrase was known to Gregory of Nyssa, so it goes back to a period earlier than its manuscript support would indicate (though it has insufficient attestation to be taken as original).