David is comparing us to a tree. He is saying that when a person meditates on the Scripture, no matter where God plants them, He will bring

Proverbs 30:6 "Do not add to His words or He will reprove you, and you will be proved a liar" This proverb on not adding to God's words follows a section on God's revelation about Himself. There is regularly speculation about God. This speculation often goes to bizarre lengths in trying to understand God. It is better to realize that God is past figuring out and that anything that we compare Him to He is utterly unlike. As Isaiah says many years later: To whom will you liken