God exercises our hearts and our faith in delaying at times to give the answer to our prayers. The earnestness of our prayers will be according to the exigency of our need, and the consciousness that He alone can give the answer. The heart is exercised and kept in dependence, waiting on Him for the reply. Faith is kept alive. Other sources are not looked to when the soul has learned that He alone can do what is needed. It is a mighty engine—that of prayer—fitting expression of the new born soul's dependence on God in contrast to that nature which ever would be independent of Him, though it cannot escape His righteous judgment.
Daniel had to wait in fastings and mournings for three whole weeks at one time before he received the reply (chap. 10). At another time, "While I was speaking," he says, the answer came (chap. 9). It marks the fact that we are not indifferent to the result when the heart can in earnest entreaty wait on God.
We may find, like Paul, that it is better for us that our desires are withheld. He learned also the reason why they were withheld, after his thrice-repeated prayer; thus he could boast in that which was the taunt of his enemies, and the trial of his friends (2 Cor. 12).
In the midst of our cares and conflicts we have to "be careful for nothing," but to let our "requests be made known unto God." He who has no cares—God—keeps our hearts and minds through Christ Jesus. But we have to "continue in prayer." We have also to "watch in the same," and withal "with thanksgiving" for His ever opened ear. One of the exhortations in Romans 12 is "continuing instant in prayer"—"pursuing" as it might be.
The very importunity of the man at the unseasonable hour of midnight, was the occasion of his obtaining the loaves (Luke 11:88I say unto you, Though he will not rise and give him, because he is his friend, yet because of his importunity he will rise and give him as many as he needeth. (Luke 11:8)). One can lay down no rules in such cases. The truly exercised heart gets its own answer from God. At times we can with simple confidence make known and commit the request to God. At others the heart is conscious that it cannot but cry to God until it is at rest in the petition. He will not give it till His own time, and meanwhile the soul is kept in earnest exercise; faith is tested, and patience tried, and the heart watches and waits on Him. Again, such is the confidence that we have in Him, that if we ask anything according to His will, He hears us; and if we know that He hears us, we know that we have the petitions that we desired of Him (1 John 5:14, 1514And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us: 15And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him. (1 John 5:14‑15)). He listens to everything which is in accordance with His will. He cannot fail in power, and we get the reply. The true heart desires nothing contrary to His mind and will.
When I am asked for an Old Testament instance of restoring grace, I point to David; if asked for a New Testament one, I point to Peter.