Charles Ellicott Commentary Psalms 147:13

"For he hath strengthened the bars of thy gates; He hath blessed thy children within thee." — Psalms 147:13 (ASV)

For He has strengthened.— An allusion to the new fortifications of the restored city is probable, though the expression is plainly figurative of security and peace.

With the second clause, compare Isaiah 60:17-18.