Psalm 8:2 — Out of the mouth of babes and sucklings hast thou ordained strength because of thine enemies, that thou mightest still the enemy and the avenger.
I have a greatnephew. The five year old son of my nephew made a wonderfully wise comment yesterday, about life’s unpredictable ups and downs. “Every day is different dad. Some days my table eats first, and some days we don’t.” Apart from the verse appealing to the potluck supper fan in me (how come our table is nearly always called last to eat?) it reminded me of the (sometimes unconscious) wisdom of children. Being reminded of the wisdom of children I was reminded also that children can sometimes astonish us by their love of God. In its turn that reminded me of this verse from Psalm 8.
Jesus quotes this verse after He has cleansed the temple, and the children cried out in wonder:

And when the chief priests and scribes saw the wonderful things that he did, and the children crying in the temple, and saying, Hosanna to the Son of David; they were sore displeased, and said unto him, Hearest thou what these say? And Jesus saith unto them, Yea; have ye never read, Out of the mouth of babes and sucklings thou hast perfected praise? (Matthew 21:15-16)

John addresses “little children” in his first letter and this might suggest that the psalmist might have been talking not so much of actual “babes” but of spiritual children. F. W. Grant comments ”

But yet for this He will establish praise out of the mouth of babes and sucklings; that is, I doubt not, of new-converted souls, humbled and brought down to such conscious littleness and weakness as this implies. We have again from His lips such a comparison in the well-known words, “Except ye be converted and become as little children, ye shall in no wise enter into the kingdom of heaven.” Thus we see clearly why He must produce such praise in order that the kingdom may come: the heirs of it must be made ready.

The words “ordained strength” might seem different from the idea of “perfected praise” which as the phrase that Jesus used. In fact the ideas are very close. A more exact translation might be “lay the foundation for glory”. That is, the children — literal or spiritual — are giving, from their innocent hearts, the most powerful witness to God’s glory.
Jesus said “Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven.” (Matthew 18:3). I think this idea of this purest testimony to God’s glory coming from the hearts and mouths of babes and sucklings is wonderful. It makes me want to become, again “as a little child”.