Ask, and it shall be given you ... - There are here three different forms presented of seeking the things which we need from God - asking, ‘seeking, and knocking. The latter is taken from the act of knocking at a door for admittance. See Luke 13:25; Revelation 3:20. The phrases signify to seek with earnestness, diligence, and perseverance. The promise is, that what we seek shall be given us. It is of course implied that we seek with a proper spirit, with humility, sincerity, and perseverance. It is implied, also, that we ask the things which it may be consistent for God to give - that is, things which he has promised to give, and which would be best for us, and most for his own honor, 1 John 5:14. Of that God is to be the judge. And here there is the utmost latitude which a creature can ask. God is willing to provide for us, to forgive our sins, to save our souls, to befriend us in trial, to comfort us in death, to extend the gospel through the world. Man “can” ask no higher things of God; and these he may ask, assured that he is willing to grant them.
Christ encourages us to do this by the conduct of parents. No parent turns away his child with that which would be injurious. He would not give him a stone instead of bread, or a serpent instead of a fish. God is better and kinder than the most tender earthly parents; and with what confidence, therefore, may we come as his children, and ask what we need! Parents, he says, are evil; that is, are imperfect, often partial, and not unfrequently passionate; but God is free from all this, and therefore is ready and willing to aid us.
Every one that asketh receiveth - That is, every one that asks aright; that prays in faith, and in submission to the will of God. He does not always give the very thing which we ask, but he gives what would be better. A parent will not always confer the “very thing” which a child asks, but he will seek the welfare of the child, and give what he thinks will be most for its good. Paul asked that the thorn from his flesh might be removed. God did not “literally” grant the request, but told him that his “grace” should be “sufficient” for him. See the notes at 2 Corinthians 12:7-9.
A fish - A fish has some resemblance to a serpent; yet no parent would attempt to deceive his child in this. So God will not give to us that which might appear to be of use, but which would be injurious.