1 Your Love remembers, that in two Psalms, which have been already treated of, we have stirred up our soul to bless the Lord, and with godly chant have said, “Bless thou, O my soul, the Lord.” If therefore we have stirred up our soul in those Psalms to bless the Lord, in this Psalm is well said, “May God have pity on us, and bless us”. Let our soul bless the Lord, and let God bless us. When God blesses us, we grow, and when we bless the Lord, we grow, to us both are profitable.
He is not increased by our blessing, nor is He lessened by our cursing. He that curses the Lord, is himself lessened: he that blesses the Lord, is himself increased. First, there is in us the blessing of the Lord, and the consequence is that we also bless the Lord. That is the rain, this the fruit. Therefore there is rendered as it were fruit to God the Husbandman, raining upon and tilling us. Let us chant these words with no barren devotion, with no empty voice, but with true heart.
For most evidently God the Father has been called a Husbandman. The Apostle says, “God's husbandry you are, God's building you are.” In things visible of this world, the vine is not a building, and a building is not a vineyard: but we are the vineyard of the Lord, because He tills us for fruit; the building of God we are, since He who tills us, dwells in us. And what says the same Apostle? “I have planted, Apollos has watered, but the increase God has given. Therefore neither he that plants is anything, nor he that waters, but He that gives the increase, even God.” He it is therefore that gives the increase.
Are those perchance the husbandmen? For a husbandman he is called that plants, that waters: but the Apostle has said, “I have planted, Apollos has watered.” Do we enquire whence himself has done this? The Apostle makes answer, “Yet not I, but the Grace of God with me.” Therefore wherever thou turn you, whether through Angels, you will find God your Husbandman; whether through Prophets, the Same is your Husbandman; whether through Apostles, the very Same acknowledge to be your Husbandman. What then of us? Perchance we are the labourers of that Husbandman, and this too with powers imparted by Himself, and by Grace granted by Himself....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)