The Responsorial Psalm say that the man who delights in the law of the Lord and meditates on it day and night is like a tree planted by living water. It yields its fruit in due season, and its leaves never fade.
Jeremiah in the first reading contrasted such a man with one who trusts in human beings, who seeks his strength in the flesh. By contrast he is like a barren bush in a lava waste.
One time I wanted to give a homily with the two trees contrasting those who trust in the flesh with those who delight in the Lord. I thought I would get a dried up bush and a gloriously healthy one, and put them in large pots in front of the altar rail for my homily..
I went to that tree nursery on Herschel, and a young clerk, seeing me picking around in the back of their lot, came out; and he said he knew the place inside and out, and he could find me just what I needed.
But when I told him I wanted a healthy little bush and a dried up one to illustrate a homily, the young stepped back. He said, “I better go get the boss.”
The running water in Jeremiah and in the first Psalm represent the fresh insights the just man receives from being in continuous contact with God.