Our bodies belong to God, but He has bestowed their care on us as a stewardship responsibility to glorify God in our body as well as our spirit. In the parable, Jesus mentions "unrighteous mammon" (verses 9, 11), which He also terms "what is least" (verse 10) and "what is another man's" (verse 12). Each term is synonymous with the other two.
Jesus does not say to ignore these. He simply points out that they are secondary to the "true riches" (verse 11), "what is your own" (verse 12), and "[what] is much" (verse 10). Similarly, each of these is synonymous with the other two. He points to a direct connection between the two levels of responsibility by saying, "He who is faithful in what is least is faithful also in much; and he who is unjust in what is least is unjust also in much" (verse 10). Care of our body falls within the parameters of unrighteous mammon, what is least and what is another man's.
John W. Ritenbaugh
Eating: How Good It Is! (Part One)
The manager of an estate, accused of wasting the owner's goods, cunningly reasons through the situation using his worldly wisdom. However, he continues to deal deceitfully with the rich man's estate. By clever thinking, he devises a plan to defraud his master still more and prepare the way for future employment. He turns the owner's debtors into his friends by forgiving up to half their debts. Reluctantly, the master commends the unjust steward for dealing shrewdly in the worldly ways of cleverness, level-headedness, and forethought. The master does not commend him for wasting his estate, for which he fires him.
Martin G. Collins
Parable of the Unjust Steward