This verse is a refrain which is repeated in Psalm 46:11.
The phrase “Yahweh sebaoth immanu” (The Lord of hosts is with us
) of the refrain is also found fifty-four times in the first thirty-nine chapters of the book Isaiah. It is a popular phrase with both psalmists and prophets, and with good reason. For decades, Judah had been relying on Egypt to be with them instead of the Lord. Isaiah kept prophesying against this. Their creed should have been God with us,
not Egypt with us
!
7 The LORD of hosts is with us; the God of Jacob is our fortress. Selah