As long as I am in the world, I am the light of the world.” Having said these things, he spit on the ground and made mud with the saliva. Then he anointed the man’s eyes with the mud and said to him, “Go, wash in the pool of Siloam” (which means Sent). So he went and washed and came back seeing. —John 9:5-7 ESV
J.C. Ryle, with an important reminder:
In healing the blind man He might, if He had thought fit, have merely touched Him with his finger, or given command with His tongue. But He did not rest content with doing so. We are told that “He spit on the ground, and made clay of the spittle, and He anointed the eyes of the blind man with the clay.” In all these means of course there was no inherent healing virtue. But for wise reasons the Lord was pleased to use them.
We need not doubt that in this, as in every other action of our Lord, there is an instructive lesson. It teaches us, we may well believe, that the Lord of heaven and earth will not be tied down to the use of any one means or instrumentality. In conferring blessings on man, He will work in His own way, and will allow no one to prescribe to Him. Above all, it should teach those who have received anything at Christ’s hands, to be careful how they measure other men’s experience by their own. Have we been healed by Christ, and made to see and live? Let us thank God for it, and be humbled. But let us beware of saying that no other man has been healed, except he has been brought to spiritual life in precisely the same manner. The great question is–“Are the eyes of our understanding opened? Do we see? Have we spiritual life?”–Enough for us if the cure is effected and health restored. If it is, we must leave it to the great Physician to choose the instrument, the means, and the manner–the clay, the touch, or the command.
Knowing God through His Word ... Day by Day 
This is a terrific post. It is writing like this that makes me happy to follow your blog. I could not help but wonder if, in addition to your moving explanation that Jesus as the Great Physician is not limited to any one instrument for healing, nor can He necessarily be predicted, nor behave in any manner consistent with our imaginations, expectations, or beliefs, but He interestingly chose dirt, mixed with His spittle, to heal a man. Man, whom He made FROM DIRT. FROM THE VERY GROUND. I once heard it said that even if scientists one day find a way to create life in a laboratory by simply putting together the compounds and enzymes and gases needed to create and support life, let man try creating the VERY BUILDING BLOCKS THEMSELVES. God is the one who made the raw materials!