By referring to Melchizedek, the writer indicated that Christ was a different sort of priest. He was not a priest in the tradition of Aaron, who was of the house of Levi and inherited his priesthood.
Christ was a priest by divine appointment. He does not do his work inside the earthly tabernacle as the Levitical priests did. He is a priest of a different order and is in the heavenly realm. Christ is the great high priest who overcame sin and death and ushered in the rule of peace.
In Mark, this controversy about the Sabbath took place in the synagogue in Capernaum. It was centred on whether healing the man's hand would be considered work because no work was to be done on the Sabbath. Jesus presented his argument on healing, saying it would be the same as saving a life and should be acceptable. Here Jesus did nothing other than asking the man to stretch out his hand, and it was healed. That was enough to anger the Pharisees, and they began to plot against Jesus. Jesus was deeply saddened by their hardness of heart.
Do we answer Jesus' call to help others, or do we turn away?
Lord, may my worship be demonstrated in the way I respond to others with love.