Exodus 25:3 - Ellicott's Commentary On The Whole Bible

Gold, and silver, and brass. — The Israelites had brought out of Egypt (1) their ancestral wealth — the possessions of Abraham and the accumulations of Joseph, and (2) the rich gifts received from the Egyptians at the moment of their departure. They had added to their wealth by the plunder of the Amalekites. Thus they possessed a considerable store of the precious metals; and there is no difficulty in supposing that they furnished the gold needed for the tabernacle without seriously impoverishing themselves. The silver, which was of small amount comparatively, appears ultimately to have been furnished in another way (Exodus 30:12-16; Exodus 38:25-28) The brass, or rather bronze, for brass seems to have been unknown at this time, was small in amount (Exodus 38:29), and of no great value. It would have constituted no serious drain on the resources of the people.