Expositor's Bible Commentary Commentary Mark 3:2

"And they watched him, whether he would heal him on the sabbath day; that they might accuse him." — Mark 3:2 (ASV)

Mark does not specifically identify the opposition here, though he clearly means Pharisees and the teachers of the law (cf. Lk 6:7). Since Jesus had already raised suspicions in their mind because of his unorthodox actions, these men were present in the synagogue to spy on Jesus, “looking for a reason to accuse” him. They were convinced of his power to perform miracles, but were wondering if he would break rabbinic law that allowed healing on the Sabbath only if that life was actually in danger.