Verse 2 continues:

Out of the mouths of babes
and sucklings
You have established strength
Because of Your adversaries,
To stop the enemy and the
avenger.

Babes and sucklings refer to man, and the emphasis in this verse is upon God using man to deal with the enemy. The Lord Jesus quoted this verse in Matthew 21:16: "Out of the mouth of infants and sucklings You have perfected praise." These words mean that the enemy may do all he can, but it is not necessary for God Himself to deal with him. God will use babes and sucklings to deal with him. What can babes and sucklings do? It says, "Out of the mouths of babes and sucklings You have established strength." God's desire is to obtain men who are able to praise; those who can praise are those who can deal with the enemy.

In verses 3 through 8 the psalmist says:

When I see Your heavens,
the works of Your fingers,
The moon and the stars,
which You have ordained,

What is man, that You
remember him,
And the son of man, that You
visit him?

You have made him somewhat
lower than angels
And have crowned him with
glory and honor.

For You have caused him to rule
over the works of Your hands;
You have put all things under
his feet:

All sheep and oxen,
As well as the beasts of the
field,

The birds of heaven and the fish
of the sea,
Whatever passes through the
paths of the seas.