Why did Jesus’ use spittle mud to heal a deaf and mute man?

There some people brought to him a man who was deaf and could hardly talk, and they begged Jesus to place his hand on him. After he took him aside, away from the crowd, Jesus put his fingers into the man’s ears. Then he spit and touched the man’s tongue. He looked up to heaven and with a deep sigh said to him, ‘Ephphatha!’ (which means “Be opened!”). At this, the man’s ears were opened, his tongue was loosened and he began to speak plainly. Jesus commanded them not to tell anyone. But the more he did so, the more they kept talking about it. People were overwhelmed with amazement. ‘He has done everything well,’ they said. ‘He even makes the deaf hear and the mute speak.’”