Luke 6:8

But he knew their thoughts; and he said to the man that had his hand withered, Rise up, and stand forth in the midst. And he arose and stood forth. And Jesus said unto them, I ask you, is it lawful on the sabbath to do good, or to do harm? to save a life, or destroy it?

He knew their thoughts ... Why downgrade this by a comment that "This required no special knowledge on his part"?[9] The clear intention of Luke, in these words, was that of showing the omniscience of Jesus (John 2:25).

To save a life, or destroy it ... Jesus thus announced the principle that the withholding of good that may be done is equivalent to doing harm, and that refusing to save a life that could be saved is the same as destroying it. The Old Testament plainly taught that the life, even of a beast which had fallen into a pit, could be saved on the sabbath; and Jesus extended the principle, as should have been obvious to the Pharisees, as applicable to men also. Here too is subtle appeal to their consciences. The Pharisees had already decided to kill Jesus (John 5:18); and here they were, on a sabbath day, laying a net to capture Jesus with the intent of killing him and yet THEY would allege sin against Jesus for healing a man on that same day. As Miller put it, "While Jesus was saving a life on the sabbath, they were using the sabbath to take counsel how they might destroy him.[10]

[9] Ray Summers, op. cit., p. 71.

[10]Donald G. Miller, The Layman's Bible Commentary (Richmond, Virginia: John Knox Press, 1959), Vol. 18, p. 77.