And God said, “Let the earth sprout vegetation, plants yielding seed, and fruit trees bearing fruit in which is their seed, each according to its kind, on the earth.” And it was so.
11. Let the earth bring forth grass Hitherto the earth was naked and barren, now the Lord fructifies it by his word. For though it was already destined to bring forth fruit, yet till new virtue proceeded from the mouth of God, it must remain dry and empty.
The third day's work is related in these verses - the forming of the sea and the dry land, and the making of the earth fruitful. Hitherto the power of the Creator had been exerted and employed about the upper part of the visible word; the light of heaven was kindled, and the firmament of heaven fixed: but now he descends to this lower world...
Commenting on Genesis 1:9-13
And God said, let the earth bring forth grass,.... Which had been impregnated by the Spirit of God that moved upon it when a fluid; and though now become dry land, it retained sufficient moisture in it, and was juicy and fit to produce vegetables; and especially as it had the advantage of the expanded air about it, and the warmth of the primordial light...