Mark 3:3

And he saith unto the man that had his hand withered, Stand forth. And he saith unto them, Is it lawful on the sabbath day to do good, or to do harm? to save a life, or to kill? But they held their peace.

Stand forth ... Christ accepted the challenge of his enemies. He would indeed heal the man on the sabbath day; but first, he would contrast his own act of saving mercy with their act, also performed on the sabbath day, of killing the Saviour of the world, that being their only purpose, which objective they pursued constantly, on sabbath days as well as all other days. But, if the Pharisees were blind to the inconsistency which accepted their own murderous actions as "lawful" sabbath day conduct, while at the same time condemning such an act as Jesus would do as "unlawful" on the sabbath, the people were not so blind and could easily see the difference.

To save a life, or to kill ... Christ was about to "save a life" from pain, inability, and frustration. The Pharisees were present for the purpose of killing Jesus. The contrast was dramatic, and there could have been no better example of opposite purposes of Satan and Christ than that which precipitated the stark, ugly incident here. The Pharisees themselves were speechless when Jesus called attention to it.

But they held their peace ... What THEY were doing was satanic and malignant; and they were stunned into silence by Jesus' obvious reference to their evil employment on the sabbath.