John Calvin Commentary Acts 28:20

"For this cause therefore did I entreat you to see and to speak with [me]: for because of the hope of Israel I am bound with this chain." — Acts 28:20 (ASV)

For the hope of Israel. We must understand much more by these words than Luke expresses, as we gather from the answer where the Jews speak of the sect; namely, Paul repeating his speech, which Luke omits.

Therefore, Paul spoke of Christ so that it might plainly appear that neither the law nor the temple profited the Jews anything without Him, because the covenant of adoption is grounded in Him, and the promise of salvation is confirmed in Him. Nor did they doubt that the restoring of the kingdom depended upon the coming of the Messiah; and even at that time, their misery and decay increased their hope and desire for Him.

Therefore, Paul says for good reasons that he is bound for the hope of Israel. By this we are also taught that no one hopes correctly except the one who looks to Christ and His spiritual kingdom; for when He places the hope of the godly in Christ, He excludes all other hopes.