What you are seeing in the quoted passage is an example of Hebrew poetry. If you read the Psalms, Proverbs, or much of any of the prophets, you will see a very clear pattern time and again: The author will state something, and then re-phrase that statement. Even though Luke is a Greek, he is relating something that took place in a culture dominated by these ...
I appears that Paul quoted from the book of Luke which would date Luke prior to Paul's death. 64-67 Ad
1 Tim. 5:18 For the Scripture says, “You shall not muzzle the ox while he is threshing,” and “The laborer is worthy of his wages.” 19 Do not receive an accusation against an elder except on the basis of two or three witnesses.
Luke 10:5 Whatever ...
If you accept its own testimony then Luke was written:-
Before the Acts of the Apostles and by the same author as the writer of Acts (compare Acts 1:1 with Luke 1:1-4);
The author of Acts was, at times, a companion of Paul on his missionary journeys:
about 49 AD, Acts 16:10-18;
about 54-57 AD, Acts 20:4-21:19; and
about 59-62 AD, Acts 27:1-28:30.
Why the Gospel of Luke belongs in the Bible
Regardless of the dating, the Gospel of Luke belongs to the Bible because it contains authoritative teaching of Jesus to guide Christians as well as authoritative reports of who Jesus is (how he was incarnated into a baby, how his divinity was affirmed from heaven in baptism and transfiguration) and what he did (...