What does Matthew 7:10 mean?

Christ has asked, "Would you give your son a stone if he asked for bread?" (Matthew 7:9) as part of His Sermon on the Mount (Matthew 5:1–2). Now He asks, "Would you give your son a serpent if he asks for fish?" The main idea is that good human fathers don't harm or spite their children when given requests. Scholars also point out that a large stone can look like a small loaf of bread, and a snake can look like a piece of prepared fish. If so, Jesus is not merely speaking of giving good things, but also the idea that God would not respond to sincere requests with deception and death.

The following verse clarifies why Jesus is asking this. He's answering an unspoken question from His listeners: Why would God listen for my prayers? Why would He give when I ask, answer when I knock, or allow me to find what I seek from Him? This is a common question of skeptics, even today: why would an all-powerful God care about my prayers?

Jesus' rhetorical questions reveal the reason: God is a good Father who would never give evil or emptiness when asked for good. We should notice here that the requests from this imagined child are for bread and fish, the most common foods eaten in this time and place near the Sea of Galilee. In other words, Jesus pictures a request to have a need met, not a request for great luxury or power or fame. A good Father will not turn away such a request if it is in his power to grant it—and all things are within God's power.