MIDRASH TEHILLIM
1.....(8.4)
From the mouths of infants and sucklings You have established strength...
...God said to the people of Israel [at the time of giving the Torah], You bring Me sureties who are not in debt to Me.
When the people of Israel asked, Who are those not in debt to You?
God answered, Infants
Whereupon the people of Israel brought sucklings at their mother's breasts, and pregnant women whose wombs become transparent as glass so that the embryos in the wombs could see God and speak with Him.
And God asked the sucklings and the embryos, Will you be sureties for your fathers, so that if I give them the Torah they will live by it, but that if they do not, you will be forfeited because of them?
They replied, Yes.
When God said to them, I am the LORD Your God (Shemot/Exodus 20:2), they replied, Yes.
When God said to them, You will not have any other gods before Me (Shemot/Exodus 20:3), they replied, Yes.
And so, as sureties for their fathers, at every utterance they replied Yes, when God said You will, and they replied, No, when God said You will not.
Thereupon, God declared, Out of your mouths, then, I give the Torah.
Strength here [in this verse] meaning Torah
2.....(8.5)
...because of Your adversaries, to put an end to enemy and avenger.
The term adversaries implying two adversaries, and the phrase -
the enemy and the avenger, implying two more adversaries in allusion to the four kingdoms.