Yes He did but we still have to understand it correctly and it is not to be interpreted as a definitive doctrinal statement.
Jesus taught Jews how Jews should have been living under the Law.
They called him "Rabbi."
The Gospels are so beautiful in what it teaches, we too easily miss that what Jesus taught was to Israel,
and about how the Jews should have been living at that time!
It was the Apostle Paul that later on God raised up to teach all believers how all of God's children should walk spiritually.
Legalism appeals to the thick headed.
“Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God, and saying,
The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.”
Mark 1:14-15 KJV
“And
this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.”
Matthew 24:14
“And Jesus came and spake unto them, saying,
All power is given unto me in heaven and in earth.
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.”
Matthew 28:18-20 KJV
“And he said unto
them, Go ye into all the world, and preach the gospel to every creature. He that believeth and is baptized shall be saved;
but he that believeth not shall be damned.”
Mark 16:15-16
The apostle Paul
“After that, he was seen of James;
then of all the apostles. And last of all he was seen of me also, as of
one born out of due time. For
I am the least of the apostles, that am not meet to be called an apostle, because I persecuted the church of God.
…..Therefore whether it were I or they, so we preach, and so ye believed.”
1 Corinthians 15:7-9, 11 KJV
“And Paul dwelt two whole years in his own hired house, and received all that came in unto him,
preaching the kingdom of God, and teaching those things which concern the Lord Jesus Christ, with all confidence, no man forbidding him.”
Acts 28:30-31 KJV
It is rather obvious that the doctrine never changes and Paul eas one of twelve apostles chosen sent by Jesus preaching the one and only gospel