1 Corinthians 2:16 ESV

Isaiah 40:13-14 ESV
Who has measured the Spirit of the Lord, or what man shows him his counsel? Whom did he consult, and who made him understand? Who taught him the path of justice, and taught him knowledge, and showed him the way of understanding?

John 15:15 ESV
No longer do I call you servants, for the servant does not know what his master is doing; but I have called you friends, for all that I have heard from my Father I have made known to you.

John 16:13-16 ESV
When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He will glorify me, for he will take what is mine and declare it to you. All that the Father has is mine; therefore I said that he will take what is mine and declare it to you. “A little while, and you will see me no longer; and again a little while, and you will see me.”

Romans 11:34 ESV
“For who has known the mind of the Lord, or who has been his counselor?”