John Calvin Commentary Exodus 25:3

"And this is the offering which ye shall take of them: gold, and silver, and brass," — Exodus 25:3 (ASV)

And this is the offering. Therefore, what I have said before is further developed, namely, that what the poor offer from their little will not be eclipsed by the abundance of the rich, since God is pleased to count goats' hair among the sacred offerings no less than gold, purple, and precious stones.

Again, by the varied and numerous contributions, He would show, as if in a mirror, that a variety of gifts are necessary for building the spiritual temple, as Paul sets forth in Romans 12 and 1 Corinthians 12.

The generosity of the rich was indeed more splendid; but, as they did not hesitate to mix their gold and silver, blue, purple, and precious stones with brass, iron, and other common materials, so also, today, those who aid the edification of the Church by their more excellent gifts admit into fellowship, without contempt or dislike, poor fellow believers to whom it has not been given to equal them.