The answer is: Because the Pharisees criticised him for eating with publicans and sinners

Matthew 9 vs 12

In Matthew 9:12, when Jesus declares that "They that be whole need not a physician, but they that are sick," he uses a striking metaphor that beautifully paints his mission. His statement comes right after the Pharisees quizzed his disciples about his choices of companionship. It's almost like Jesus is playfully flipping the script on them! Instead of maintaining an air of separation like the Pharisees, who prided themselves on religious purity, Jesus showcases grace by surrounding himself with those marginalized by society.

While the Pharisees saw purity in isolation, Jesus introduces a defined purpose: healing. The people 'sick' in this context weren't just battling physical ailments but were often viewed as spiritually or morally flawed. This detour into the life of everyday outcasts—a tax collector like Matthew (who penned this passage), or sinners—shows that the spiritual journey includes everyone, particularly those who have felt left out.

Trivia alert: Did you know that this isn't the first time physicians show up in scripture? In fact, Luke, the doctor who's gospel recounts many such healing moments, would have likely appreciated the metaphorical implications of Jesus’ words. He understood human frailty. Plus, the medical practices of the day were quite fascinating, ranging from herbal remedies to miraculous healers. So, next time you think about healing, remember, it involves much more than just the physical; it's about holistic care—a mental and spiritual rejuvenation mission we can all aspire to!