I tell you - The Latin Vulgate here adds, “if he shall continue knocking.” Though this is not in the Greek, yet it is indispensable that it should be understood in order to the sense. Knocking “once” would not denote “importunity,” but it was because he “continued” knocking.
His importunity - His troublesome perseverance; his continuing to disturb the man, and refusing to take any denial. The word “importunity” denotes perseverance in an object, without any regard to time, place, or circumstances - an improper perseverance. By this the man was influenced. Rather than be disturbed he would rise and give what was asked. This is to be applied to God in no other sense than that he often hears prayers and grants blessings even “long after” they appear to be unanswered or withheld. He does not promise to give blessings “at once.” He promises only that he will do it, or “will answer” prayer. But he often causes his people long to wait. He tries their faith. He leaves them to persevere for months or years, until they “feel” entirely their dependence on him, until they see that they can obtain the blessing in no other way, and until they are “prepared” to receive it. Often they are not prepared to receive it when they ask it at first. They may be proud, or have no just sense of their dependence, or they would not value the blessing, or it may “at that time” not be best for them to obtain it. But let no one despair. If the thing is for “our” good, and if it is proper that it “should” be granted, God will give it. Let us first ask aright; let us see that our minds are in a proper state; let us feel our need of the blessing; let us inquire whether God has “promised such” a blessing, and “then” let us persevere until God gives it. Again: people, when they ask anything of God, often give over seeking. They go “once,” and if it is not granted they are discouraged. It is not so when we ask anything of people. “Then” we persevere; we take no denial; we go again, and “press” the matter until we obtain it. So we should of God. We should go again and again, until the prayer is heard, and God grants what we ask of him.