John Calvin Commentary John 6:13

"So they gathered them up, and filled twelve baskets with broken pieces from the five barley loaves, which remained over unto them that had eaten." — John 6:13 (ASV)

And filled twelve baskets. When four thousand men were fed with seven loaves, Matthew relates that the number of baskets filled with fragments was exactly the same as the number of the loaves (Matthew 15:37). Therefore, since a smaller quantity was sufficient for a greater number of men, and since the quantity left was nearly double, from this we see more clearly how valuable that blessing of God is, a sight to which we deliberately shut our eyes.

We should also observe, in passing, that although Christ commanded them to fill the baskets to illustrate the miracle, He also exhorted His disciples to frugality when He said, Gather the fragments which are left, that nothing may be lost; for the increase of God's bounty should not be an incitement to luxury.

Therefore, let those who have abundance remember that they will one day give an account of their excessive wealth if they do not carefully and faithfully apply their surplus to purposes that are good and that God approves.