Isaiah 26:1

We have a strong city - In opposition to the city of the enemy, which God hath destroyed, Isaiah 25:1-12 (note). See the note there.

Salvation - for walls and bulwarks - חומת וחל chomsoth vachel, walls and redoubts, or the walls and the ditch. חל chel properly signifies the ditch or trench without the wall; see Kimchi. The same rabbin says, This song refers to the time of salvation, i.e., the days of the Messiah.

In that day shall this song be sung - By the people of God, on their restoration to their own land.

We have a strong city - Jerusalem. This does not mean that it was then strongly fortified, but that God would guard it, and that thus it would be strong. Jerusalem was easily capable of being strongly fortified Psalm 25:2; but the idea here is, that Yahweh would be a protector, and that this would constitute its strength.

Salvation will God appoint for walls - That is, he will himself be the defender of his people in the place of walls and bulwarks. A similar expression occurs in Isaiah 60:18 (see also Jeremiah 3:23, and Zechariah 2:5).

Bulwarks - This word means properly bastions, or ramparts. The original means properly a pomoerium, or antemural defense; a space without the wall of a city raised up like a small wall. The Syriac renders it, Bar shuro, - 'Son of a wall,' meaning a small wall. It was usually a breastwork, or heap of earth thrown up around the city, that constituted an additional defense, so that if they were driven from that they could retreat within the walls.

26:1 In that day - When God shall do such glorious works, as are described in the foregoing chapter. Sung - In the church of God.A city - Jerusalem, or the church, which is often compared to a city.For walls - God's immediate and saving protection shall be to his church instead of walls.