John Goldingay talks about blessing as one of the aspects of “God speaking” in creation. God’s speech is life-giving. He mentions something Genesis Rabbah says concerning the fact that Torah does not start with the first letter of the Hebrew alphabet, ‘aleph. And what does that have to do with blessing? Here is what he says,

“Thus blessing “is not simply a friendly wish” but “a bestowal of life-force… an act whereby the power-for-life monopolized by Yahweh generously is transmitted to Abraham and his descendants” (Brueggemann, Theology of the Old Testament [Minneapolis: Fortress, 1997], p. 165) — and here to humanity as a whole and to other living creatures. God shares power-for-life with the animal world. The prominence of the blessing theme makes for a pointed contrast with the gloomy vision of other Middle Eastern stories of the origins or the world and humanity, as well as with the troubled experience of Israel in; for instance, the exile. Genesis Rabbah 1:10 (on Gen 1:1) sees here another significance in the fact that Scripture begins with a bet, not an ‘alep, the second letter of the alphabet rather than the first, since b is the first letter of the word for blessing (whereas ‘aleph is the first letter of the word for curse). “Bless” has the first word in Scripture” (Israel’s Gospel, 54).

Side Note:

I was curious to find out when blessing and cursing first occur in the Bible. Blessing first makes its appearance in Genesis 1:22:

God blessed them, saying, “Be fertile and increase, fill the waters in the seas, and let the birds increase on the earth.”

The noun blessing is used for the first time in Gen 12:2.

I could not find the noun for curse using the root ארר (which is what I think the midrash has in mind), since it is usually קללה which HALOT defines as a curse-formula by which someone or something is designated as cursed (ארור). So the first time the verbal form of ארר is used in the Bible is in 3:14:

Then the LORD God said to the serpent, “Because you did this, More cursed shall you be Than all cattle And all the wild beasts: On your belly shall you crawl And dirt shall you eat All the days of your life.

The first time God blesses something is on the fifth day and what He blesses is specifically living beings. The interesting comment in Genesis Rabbah is that the first letter already foreshadows that. I think it is a little ironic that the first curse is also attributed to a living creature.