For three long chapters Paul has been reasoning, tracing Israel's stumbling and the Gentiles' welcome, a hardening with a boundary built into it and a mercy that reaches everyone in the end. Then, without warning, the argument stops and becomes worship. Then comes a cry, a gasp more than another point.
The word behind "inscrutable" is a striking one. It is built from the ordinary Greek word for a footprint or a track. Paul is saying that God's ways cannot be followed the way a hunter follows a trail through the woods. You can walk a long way into the wisdom of God, farther than you thought possible, and there is still no path left to trace. That is the reason for the exclamation that opens the sentence.
Then three questions, and each one expects the same answer, no one. 34"who has known the mind of the Lord, or who has been his counselor?" No one sat beside God when he planned to graft wild branches into an old olive tree, or to let Israel's hardening become the door of mercy for the nations. 35"Or who has given a gift to him that he might be repaid?" No one, because everything Paul has spent eleven chapters describing, election and calling and hardening and mercy, was owed to no one and earned by no one. It came from a depth nobody was standing in when the plan was made.
Then the sentence that gathers the whole letter into three prepositions. 36"from him and through him and to him are all things." Everything Paul has argued since the first chapter, sin's spread, the law's failure, faith's gift, Israel's stumbling, the Gentiles' grafting in, began in God, moves by God's hand, and ends aimed at God's glory. All three prepositions point at God alone, and the story is held together from outside itself.
Paul leaves the hard questions of chapters 9 through 11 unresolved. He leaves unexplained why some are hardened and others shown mercy, and how a partial hardening will one day lift. He reaches the edge of what can be traced and stops tracing. What replaces the argument is praise. 36"To him be glory forever. Amen." That is where sustained thinking about God is supposed to end up.
There is a wisdom in learning to stop where Paul stops. Not every question we bring to God gets answered the way we would answer it, with a reason attached that satisfies us. Some are answered the way Job's were, with a vision of God large enough to make the explanation unnecessary. An honest look at his greatness was always going to land on worship.
Think of the question you have carried longest, the one about a loss or a delay or a family member's unbelief. You are allowed to keep asking it. You are also allowed to do what Paul does here, and let your last word in the matter be praise to the one from whom and through whom and to whom all things are.
Prayer
Father, your ways run deeper than we can trace, and we are grateful that the parts of your plan we cannot follow are held by wisdom. Thank you that everything, our faith, our mercy, our place in this story, came from you before we could ask and moves toward your glory whether we understand it or not. When our reasoning runs out, teach us to do what Paul did and let the last word be praise. In Jesus' name, amen.