Matthew 7:7-11,  seek and you will find

7:7 “Ask, and it will be given you. Seek, and you will find. Knock, and it will be opened for you.
7:8 For everyone who asks receives. He who seeks finds. To him who knocks it will be opened.
7:9 Or who is there among you, who, if his son asks him for bread, will give him a stone?
7:10 Or if he asks for a fish, who will give him a serpent?
7:11 If you then, being evil, know how to give good gifts to your children, how much more will your Father who is in heaven give good things to those who ask him!”

(Matt 7:7-11 WEB)

Knock and it will be opened

Knocking was used within Judaism as a description of prayer and yet it was unusual for such a bold promise of an answer to be given. It may be that Jesus intended to convey, as many have suggested, that a generous God wants to grant our wishes if we would but tell him what they are. It is, however, worth noting that the proceeding two passages both address the application of wisdom in relation to giving, and, therefore, that the promise here relates specifically to the granting of such wisdom. God can, and still does, produce meals miraculously, however more often than not He prefers a different approach, that of giving us the wisdom to obtain it for ourselves. 

Bread and fish were the most basic of foodstuffs around lake Galilee. However, to a young child, stones and loaves can look superficially similar (both round and brown), as can snakes and fish (both have scales). It takes a father’s wisdom (or a mother’s) to recognise one from another and keep the child safe and provide them with the proper food.

Compared to the unadulterated goodness of God, any fathers amongst Jesus’ audience were evil (even though by our standards they might have seemed good). Yet, they still had the wisdom to discriminate between what was good for their children and what was bad. If they have the wisdom to ensure that their children only got good gifts, then how much more would that be the case for their Heavenly Father, the wisest of the wise. Hence, Jesus could be confident, not that God would provide his children’s every whim, but that when they asked, the portion that he gave them, whatever that might be, would be intended for their good rather than their harm.