O God, thou hast taught me from my youth: and hitherto have I declared thy wondrous works.
Ver. 17. O God, thou hast taught me] Happy David in such a school master. All the faithful are taught of God; outwardly by his word and works, inwardly by his Spirit: Et quando Christus magister quam cito discitur quod docetur? Nescit tarda molimina Spiritus Sancti gratia (Aug. Ambrose).