Here, 1. David pleads that God is good to all the creatures according to their necessities and capacities; as the heaven is full of God's glory, so the earth is full of his mercy, full of the instances of his pity and bounty. Not only the land of Canaan, where God is known and worshipped, but the whole earth, in many parts of which he has no homage paid him, is full of his mercy. Not only the children of men upon the earth, but even the inferior creatures, taste of God's goodness. His tender mercies are over all his works. 2. He therefore prays that God would be good to him according to his necessity and capacity: "Teach me thy statutes. Thou feedest the young ravens that cry, with food proper for them; and wilt thou not feed me with spiritual food, the bread of life, which my soul needs and craves, and cannot subsist without? The earth is full of thy mercy; and is not heaven too? Wilt thou not then give me spiritual blessings in heavenly places?" A gracious heart will fetch an argument from any thing to enforce a petition for divine teaching. Surely he that will not let his birds be unfed will not let his children be untaught.