“If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him?”
Luke 11:13 — Greek Interlinear
Church Fathers on Luke 11:13
Having laid aside the metaphor, our Lord added an exhortation, and expressly urged us to ask, seek, and knock, until we receive what we are seeking. Hence he says, And I say to you, Ask, and: it shall be given you.
The words, I say to you, have the force of an oath. For God does not lie, but whenever He makes known any thing to His hearers with an oath, he manifests the inexcusable littleness of our faith.
Now by asking, He means prayer, but by seeking, zeal and anxiety, as He adds, Seek, and you shall find. For those things which are sought require great care. And this is particularly the case with God. For there are many things which block up our senses. As then we search for lost gold, so let us anxiously seek after God. He shows also, that though He does not forthwith open the gates, we must yet wait. Hence he adds, Knock, and it shall be opened to you; for if you continue…