Psalm 110 celebrates God’s gift of a messianic king over the people and the restoration from judgment*. It echoes themes from earlier in the Psalter. This king to whom Yahweh says, “sit at my right hand, until I make your enemies your footstool,” is the same one who received the commendation, “You are my Son; today I have begotten you. Ask of me, and I will make the nations your heritage, and the ends of the earth your possession.” The king that rules from Zion stretches out his scepter over the nations and breaks them in pieces like clay pots. He is the son of man who, for a little while, was made lower than the angels but has been crowned with glory and honor and dominion. The Psalm echoes the promise of Genesis that the seed of the woman would shatter the head of the serpent. And it calls up that mysterious figure Melchizedek, the gentile priest-king who came from Jerusalem to bless Abraham after his victory in battle, and to whom Abraham gave a tenth of all the spoils. This Messiah would be a priest-king like that, blessing with bread and wine.
Fully aware of and anticipating the fulfillment of all these Messianic promises, the disciples ask Jesus: are you going to bring the kingdom now? are you going to set up your throne and crush your enemies under your feet? Is Israel going to be the great kingdom that it once was under David and Solomon?
His answer seems to brush them off: it is not for you to know times or seasons. But he isn’t brushing them off. He is just reorienting them. All through the gospels he has told them that the kingdom is not quite the kind of thing they were expecting. His authority is made manifest in his obedience to the Father. His power is displayed in his service, in laying down his life for his church. He already has all authority in heaven and on earth and he says that his disciples would receive power when he sent the Holy Spirit to them. By his Spirit, they have authority to go out to be witnesses, messengers of his resurrection, ascension, and session at the right hand of the Father. By his Spirit they have the authority to disciple the nations, teaching them to obey all that he has commanded.
*see Jim Jordan’s helpful summary of Book Five of the Psalter.