It is important to see that Nehemiah recognises the relation of God's mercy to His covenant. He perceives that the two go together, that the covenant does not dispense with the need of mercy any more than it forecloses the action of mercy. When the covenant people fall into sin, they cannot claim forgiveness as a right; nor can they ever demand deliverance from trouble on the ground of their pact with God. God does not bargain with His children. A Divine covenant is not a business arrangement, the terms of which can be interpreted like those of a deed of partnership, and put into force by the determinate will of either party. The covenant is, from the first, a gracious Divine promise and dispensation, conditioned by certain requirements to be observed on man's side. Its very existence is a fruit of God's mercy, not an outcome of man's haggling, and its operation is just through the continuance of that mercy. It is true a promise, a sort of pledge, goes with the covenant; but that is a promise of mercy, a pledge of grace. It does not dispense with the mercy of God by converting what would otherwise be an act of pure grace on His part into a right which we possess and act upon of our own sole will. What it does is to afford a channel for the mercy of God, and to assure us of His mercy, which, however, remains mercy throughout.
From another point of view the covenant and the mercy go together. The mercy follows the covenant. The expression "the uncovenanted mercies of God" has been used in bitter irony, as though any hope that depended on such mercies was poor indeed, a bare refuge of despair. But so to treat the unknown goodness of God is to discredit that "ceaseless, unexhausted love" which has given us the latest and highest and best name of God. We do not know how far the vast ocean of the lovingkindness of God extends. On the other hand, certain definite assurances of mercy are given along the lines of a covenant. Therefore it is clearly wise and right for people who possess the covenant to follow those lines. Other people who are outside the covenant may meet with wonderful surprises in the infinite Fatherhood of God; but those of His children who are in the home must expect to be treated according to the established order of the house. No doubt they too will have their grand surprises of Divine grace, for God does not tie Himself to forms and rules at home while He exercises liberty abroad. To do so would be to make the home a prison. But still His revelation of methods of grace is a clear indication that it is our duty to observe those methods, and that we have no ground of complaint if we do not receive the grace we seek when we wilfully neglect them. Here then we see the necessity of studying the revelation of the will and mind of God. That prayer has most ground of hope in it which keeps nearest to the thought and spirit of Scripture.