And a man who is clean shall gather up the ashes of the heifer and deposit them outside the camp in a clean place. And they shall be kept for the water for impurity for the congregation of the people of Israel; it is a sin offering. Numbers 19:9 (ESV)
Jesus is the fulfilment of the Red Heifer, Hebrews 9:13-14 compares the blood of Jesus to the ashes of the heifer. In the same way we read about he ready access Israel had to purification from uncleanness using the water for impurity so we have access to cleansing by the blood of Jesus. See 1 John 1:7
Now there was no water for the congregation. And they assembled themselves together against Moses and against Aaron. And the people quarreled with Moses and said, “Would that we had perished when our brothers perished before the LORD! Why have you brought the assembly of the LORD into this wilderness, that we should die here, both we and our cattle? And why have you made us come up out of Egypt to bring us to this evil place? It is no place for grain … Numbers 20:2–13 (ESV)
The Rock represented Jesus (1 Cor 10:4) from him the living waters come, Moses was meant to speak to the Rock, striking it was disobedient and disrespectful.
so that your faith might not rest in the wisdom of men but in the power of God. 1 Corinthians 2:5 (ESV)
It was common and popular in Corinth for the philosophers of the day to debate using the rhetorical skills espoused in philosophy… Paul makes a point that he did not use these methods is persuading the Corinthians concerning Christ crucified, instead he relied on the power of the Holy Spirit for their conversion. In this way their faith would be built on and reliant on God and not a man and his skill.
Yet among the mature we do impart wisdom, although it is not a wisdom of this age or of the rulers of this age, who are doomed to pass away. 1 Corinthians 2:6 (ESV)
Paul is not against sound teaching, and makes the point that the spiritual and mature are to receive this. He does make the point later that it is spiritual wisdom that can only be understood by those whose eyes have been opened spiritually. We are called to grow so we should be teachable and eager to learn.
“For who has understood the mind of the Lord so as to instruct him?” But we have the mind of Christ. 1 Corinthians 2:16 (ESV)
As believers we are filled with the Spirit of Christ and so know Christ in truth through the Spirit of Truth, unlike the wisdom gained through human ways this is granted by God’s grace through his Spirit. Having the mind of Christ is a very functional thing, and in this context is focused on the communal life of believers walking in obedience, humility and serving each other just as like Jesus our great example. To have the mind of Christ operate in our lives we must put the selfish flesh to death and humble ourselves with the same attitude Jesus had in coming to save us. See Philippians 2:2-5
For you save a humble people, but the haughty eyes you bring down. Psalm 18:27 (ESV)
We are called to walk in humility