6 Again, He says, “A certain man to whom some guest had come, went to his friend, and began to knock and say, A guest has come to me, lend me three loaves.” He answered, “I am already in bed, and my servants with me.” The other does not leave off, but stands and presses his case, and knocks and begs as one friend of another. And what says He? “I say unto you that he rises, and not because of his friendship,” but “because of the other's importunity he gives him as many as he wanted.
Not because of his friendship,” though he is his friend, but “because of his importunity.” What is the meaning of “because of his importunity?” Because he did not leave off knocking; because even when his request was refused, he did not turn away. He who was not willing to give, gave what was asked, because the other fainted not in asking. How much more then shall that Good One give who exhorts us to ask, who is displeased if we ask not? But when at times He gives somewhat slowly, it is that He is showing us the value of His good things; not that He refuses them.
Things which have been long desired, are obtained with the greater pleasure, whereas those which are given quickly, are held cheap. Ask then, seek, be instant. By the very asking and seeking you grow so as to contain the more. God is keeping in reserve for you, what it is not His will to give you quickly, that you may learn for great things to long with great desire. Therefore “ought we always to pray, and not to faint.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)