John Calvin on Exodus 25:3-7

3 And this is the offering. Hence, what I have before said is more fully continued, viz., that what the poor offer of their little will not be eclipsed by the abundance of the rich, since God deigns to reckon goats’ hair among the sacred offerings not less than gold, purple, and precious stones. Again, by the varied and manifold contributions, He would shew, as in a glass, that a variety of gifts are necessary to the building of the spiritual temple, as Paul sets forth in Romans 12 and 1 Corinthians 12. The liberality of the rich was indeed more splendid; but, as they did not scruple to mix their gold and silver, blue, purple, and precious stones, with brass, iron, and other common materials, so also, now-a-days, those who aid the edification of the Church by their more excellent gifts, admit, without contempt or dislike, into fellowship poor brethren, to whom it is not given to equal them.