Further Thought: The word translated as “steward” in a few Old Testament texts comes, not from a single word but from a phrase: asher al bayt, the “one who is on or over a house.” For example, Genesis 43:19 can be translated: “When they drew near to the steward of Joseph’s house, they talked with him at the door of the house” (NKJV).
If one considers that the family that resides in the house is part of the house itself, then what is more valuable to a person than their own home? Hence, a steward is someone being entrusted with something very valuable that, nevertheless, does not belong to him. In many ways, that makes the responsibility even greater than it would be if the steward were in charge of his or her own possessions.
This same idea is continued in the New Testament as well. “The NT takes OT ideas and joins them with first-century ideas, concepts, and words, thus enriching and enlarging the biblical teaching on stewardship. The most common Greek words used in relationship with stewardship are derived from oikos and oikia, ‘house.’ The oikonomos is one who keeps the house: the steward or manager. Oikonomiais the abstract noun, ‘management of the house,’ the meaning of which is often much broader.” – Handbook of Seventh-day Adventist Theology (Hagerstown, Md.: Review and Herald Publishing Association, 2000), p. 653.
Source: Daily Sabbath School Lessons