Charles H. Spurgeon on Psalms 133:3

The LORD commanded the blessing. It is an allusion possibly to, great persons, to a general, or an emperor: "Where the word of a king is, there is power." The centurion said, "I say to one soldier, Go, and he goeth, to another, Come, and he cometh; to a third, Do this, and he doth it." So God commandeth one ordinance, "Go and build up such a saint", and it goeth; he saith to another ordinance, "Come, and call home such a sinner", and it doth it; God's words and work go together. Men cannot enable others, or give them power to obey them; they may bid a lame man walk, or a blind man see; but they cannot enable them to walk or see: God with his word giveth strength to do the thing commanded; as in the old, so in the new creation, "He spake, and it was done; he commanded, and it stood fast:" Ps 33:9. But there the Lord commands his blessing, "even life for evermore." The stream of regeneration, or a spiritual life, which shall never cease, but still go forward and increase, till it swell to, and be swallowed up in the ocean of eternal life, "even life for evermore." —George Swinnock