Where did the chief priests find that the King of Israel was to be born?
When Herod asked the chief priests where the King of Israel was to be born, they searched the Old Testament Scriptures and found in the book of Micah that He was to be born in Bethlehem. They should have known this immediately, but they had to dig it up when questioned.
Les explains that when the wise men came to Herod asking where the King of the Jews was born, Herod was troubled and called the chief priests. They did not know the answer offhand, so they searched the Old Testament Scriptures and found in the book of Micah that He would be born in Bethlehem. Les points out Israel should have known this plainly from the Old Testament, but they were unbelieving and refused to search the Scriptures. This same pattern of unbelief appears in Romans chapter 11, where Israel should have known but refused.