Jesus tells people to be obedient and repent so they’ll be ready for the Lord’s coming, illustrating his point with a parable about a fig tree. Then he heals an old woman and a blind man on the Sabbath, which upsets the Pharisees: Luke 12:35–13:21; John 9:1–41
Everyone knew that working on the Sabbath was forbidden. Was Jesus working when He healed on the Sabbath, or was He, like the priests serving in the Temple, doing God’s work?
The Pharisees argued the first: any breach of their rules was forbidden, especially if Jesus was the one who did it. Jesus seems to argue the second: He was just doing God’s work, and explained this to the Pharisees in fairly robust language:
Luke 13:15-16You hypocrites! Each of you works on the Sabbath day! Don’t you untie your ox or your donkey from its stall on the Sabbath and lead it out for water? This dear woman, a daughter of Abraham, has been held in bondage by Satan for eighteen years. Isn’t it right that she be released, even on the Sabbath?
The argument about what is work and what isn’t work can become quite involved, as this paper about Healing on the Sabbath shows. The Logic of Healing on the Sabbath explains in more detail what was happening at the time of Jesus.