Bill,
The message that was to go to the Jews was the "gospel of the circumicision",and that message was based soley on the prophecies contained in the OT.Paul said that his message was based on "no other things than those which the prophets and Moses did say should come: That Christ should suffer,and that He should rise from the dead,and should show light unto the people,and to the Gentiles"(Acts26:22,23).
And indeed we do see that the gospel message that the Jews received was "Jesus,and the resurrection"(Acts17:18).
Since the Jews possessed the OT Scriptures.the Lord wanted them to have a meassage that could be verified by the prophecies contained in the OT.And we can see that that is exactly what happened:
"These were more noble than those in Thessalonica,in that they received the word with all readiness of mind,and SEARCHED THE SCRIPTURES DAILY,WHETHER THOSE THINGS WERE SO.Therefore,many of them believed"(Acts17:11,12).
The Lord did not want any message that could not be verified by the OT prophecies preached to the Jews.And the message that "THE LAW was no longer in effect for believers" (Ro.10:4) could not be found in the OT prophecies,so therefore that message was not to be given unto the Jews.
In fact,that message could cause confusion and perhaps some would not believe because there are some OT prophecies that do show that some form of "law" will be instituted at some point in the futue,as we see at Isaiah 2:3.
So the "gospel of the circumcision" was to be preached to the Jews,and the Jews were not to hear the "mysteries" contained in the "gospel of the uncircumcision".Therefore,Paul did not tell the Jews at Acts21 that "Christ is the end of law for righteousness to everyone who believeth".
And I believe that the Lord was telling Paul when the Jews should receive one message and when they would receive the same "good news" which the Gentiles were receiving.It seems as if the Lord was keeping Paul informed as to His purposes as time progressed (Acts26:16).
In His grace,--Jerry