What did Israel do after Christ ascended?
After Christ ascended, Israel continued rejecting the offer of the King and the Kingdom. Because of this rejection, God moved the Kingdom program into the future and inserted an undetermined period of time, during which Peter and the other apostles operated only on the Old Testament program, giving Israel further opportunity to repent.
Les teaches that as soon as Christ ascended, Israel kept on rejecting the offer of the King and the Kingdom. Consequently, God moved all of this out into the future and put in an undetermined period of time. No one knows when it will end; then the seven years will come, then Christ will return, and then the King will come and set up His Kingdom. During this interval, Peter and the other eleven operated only on what God had revealed—the Old Testament program. Peter had no concept of God turning to the Gentiles for 1900 and some years. God was giving Israel every opportunity to yet repent of what they had done to their Messiah. In the early chapters of Acts, Peter isn't talking to the church or to Gentiles.