Matthew 7:7

Ask.. seek.. knock] A climax of increasing urgency. We are to wrestle with God in prayer, as Jacob wrestled with the angel (perhaps with God Himself), and said, 'I will not let thee go, except thou bless me' (Genesis 32:26). The lesson is, 'That men ought always to pray and not to faint' (Luke 18:1).

9, 10. Bread.. stone.. fish.. serpent] A stone is like a loaf, and a serpent is like a fish, especially some fishes. The idea is that God will not mock an earnest suppliant, by appearing to answer his prayer, and giving him something which, though apparently good, is really noxious.