Psalms 127:4 - Matthew Poole's English Annotations on the Holy Bible

In the hand of a mighty man; when they are shot out of a bow by a man of great strength against his enemy, which are of great use and power, both to offend the enemy, and to defend himself. Children of the youth; children begotten in youth, as a husband or wife married in their youth are called a husband or wife of youth, Proverbs 5:18 Isaiah 54:6 Joel 1:8, and as a son begotten in old age is called a son of old age, Genesis 37:3. And these he prefers before other children in this point, partly because such are commonly more strong and vigorous than others; and partly because they live longest with their parents, and to their comfort and support, whereas children born in old age seldom come to any maturity of years before their parents death.