What does Isaiah 25:1 mean?

Many commentators see this chapter as a song of praise directly responding to the events of the last passage (Isaiah 24). God's people praise Him for His deliverance of them. His people celebrate the Lord's justice against His enemies, and for the glorious kingdom He now begins. It is possible that this song of praise is more of an overarching celebration of God's faithfulness to Israel and His victory over her enemies.

The song begins with a very personal declaration, from Isaiah to the Lord. Isaiah has emphasized the Lord's relationship with Israel and Judah as a group: the nation as a whole. This was consistent with how God interacted with His chosen people. And yet, even then, it was clear that every person needed a personal relationship with, and responsibility to, the Lord. The prophet's commitment to exalt and praise the name of his God is not dependent on what anyone else in his nation might do.

Isaiah praises the Lord for the amazing things He has done. He is likely referring to miracles or interventions beyond the realm of human ability.

He also praises the Lord for His plans. God established these plans long ago and then carried out with faithfulness and certainty. Isaiah understands that the Lord does not operate as the false gods in stories. The Lord does not change His mind or fly off in new directions in response to new circumstances. He does not destroy the earth on a whim or in a tantrum. He controls time and space and carries out events as they are meant to happen, according to His perfect plans.