Augustine of Hippo : [The fruitful trees are] in the plain, on level ground, not in rugged places, in a relatively easy life. Having things fairly easy in this life, with nothing steep or rugged, toilsome, difficult to cope with, this he calls the plain. Such is the life of many of the faithful in the church of God, who have their wives and husbands, children, families. They are like trees in the plain; they are not strong enough to climb anything steep or rugged. But only let them receive the shower; these trees too will give their fruit. — SERMON 47:25