Psalms 131:1-3 (NLT)
1 A song for pilgrims ascending to Jerusalem. A psalm of David. LORD, my heart is not proud; my eyes are not haughty. I don’t concern myself with matters too great or too awesome for me to grasp.
2 Instead, I have calmed and quieted myself, like a weaned child who no longer cries for its mother’s milk. Yes, like a weaned child is my soul within me.
3 O Israel, put your hope in the LORD—now and always.

It’s from the soul that direction comes for either reliance on the Word of God or self-generated assumptions of lofty matters. David considers thoughts coming from anything other than a source in God are of an infant soul, of very little reason for anchored hope. Rather than relying on responses from infantile worldly emotions, there is a hope to be found in the Source of life that is proven and matured in the Word, something that will never be swayed by the fickle emotions of a childish soul.