Augustine of Hippo
Catena Aurea · Lukasevangelium 11
And I say unto you, Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you. For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened. If a son shall ask bread of any of you that is a father, will he give him a stone? or if he ask a fish, will he for a fish give him a serpent? Or if he shall ask an egg, will he offer him a scorpion? 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?
(Serm. 105.) What great things the world speaks to thee, and roars them behind thy back to make thee look behind! O unclean world, why clamourest thou! Why attempt to turn him away! Thou wouldest detain him when thou art perishing, what wouldest thou if thou wert abiding for ever? Whom wouldest thou not deceive with sweetness, when bitter thou canst infuse false food?