Albert Barnes Commentary Acts 26:7

"unto which [promise] our twelve tribes, earnestly serving [God] night and day, hope to attain. And concerning this hope I am accused by the Jews, O king!" — Acts 26:7 (ASV)

Unto which promise. To the fulfillment of this promise, they hope to come; that is, they hope and believe that the promise will be fulfilled, and that they will partake of its benefits.

Our twelve tribes. This was the name by which the Jews were designated. The ancient Jewish nation had hoped to come to that promise; it had been the hope and expectation of the nation.

Long before the coming of the Messiah, ten of the twelve tribes had been carried captive to Assyria and had not returned, leaving only the two tribes of Benjamin and Judah. However, the name "the twelve tribes" would still be retained to designate the Jewish people .

Paul here says that this hope had been that of the Jewish nation. Except for the comparatively small portion of the Sadducees, the great mass of the nation had held to the doctrine of a future state. Agrippa would know this well.

Instantly. Constantly; with intensity; with an effort—en ekteneia—with zeal. This was true, for amid all the sins of the nation, they observed with punctuality and zeal the outward forms of the worship of God.

Serving God. In the ordinances and observances of the temple. As a nation, they did not serve Him in their hearts, but they kept up the outward form of religious worship.

Day and night. With unwearied zeal, with constancy and ardor (Luke 2:37). The ordinary Jewish services and sacrifices were in the morning and evening, and might be said to be performed day and night.

Some of their services, such as the paschal supper, were usually prolonged until late at night. The main idea is that they kept up the worship of God with constant and untiring zeal and devotion.

For which hope's sake. On account of my cherishing this hope in common with the great mass of my countrymen . If Paul could convince Agrippa that the main point of his offense was that which had been the common belief of his countrymen, it would show to Agrippa's satisfaction that Paul was innocent.

And on this ground Paul presented his defense: that he held only what the mass of the nation had believed, and that he maintained this in the only consistent and defensible manner—namely, that God had, in fact, raised up the Messiah, and had thus given assurance that the dead would rise.