This haftarah opens with Isaiah describing God in the same terms Genesis itself uses, the one who created the heavens and stretched them out, who spread out the earth and what comes from it, who gives breath to the people on it and spirit to those who walk on it. From that creator language the passage moves to a call: Israel has been called in righteousness to be a covenant for the people and a light to the nations, opening blind eyes and bringing prisoners out of confinement and darkness.
The passage then turns to a hymn of praise, a new song sung to God from the ends of the earth, before addressing Israel directly as a people robbed and plundered, snared in holes and hidden in prisons, a description commentators generally read against the experience of exile. It reassures that God who formed Jacob and created Israel has redeemed them by name, that they belong to God, and that when they pass through waters or fire they will not be overwhelmed or consumed.
The haftarah closes affirming that God alone is the true witness to this, that no god was formed before Him and none will be after, and that Israel itself is called to be His witness before the nations, closing on the declaration that God alone is savior.