From Luke 11:15-26
But if it is through the finger of God that I cast out devils, then know that the kingdom of God has overtaken you. So long as a strong man fully armed guards his own palace, his goods are undisturbed; but when someone stronger than he is attacks and defeats him, the stronger man takes away all the weapons he relied on and shares out his spoil.
Today Jesus is speaking about casting out devils after he is challenged by a crowd. They claim he is able to cast out devils through Beelzebul himself. But Jesus suggests to them that it is another power which allows him to cast out devils, that of the power of God. Jesus intentionally refers to the ‘finger of God’ as even God’s mere finger is powerful enough to cast out devils. How great then the power of God in His entirety if His finger has the power to do such things!