John Calvin Commentary Exodus 16:19

"And Moses said unto them, Let no man leave of it till the morning." — Exodus 16:19 (ASV)

And Moses said, Let no man. Moses here recounts that when he had commanded them all not to take more than enough for their daily food, and to gather a double portion the day before the Sabbath, some were disobedient on both points.

Regarding the first point, since God would supply their food to them just as the breast is given to babes, it was a sign of perverse unbelief that they would not depend on God’s providence but sought a provision that would last them many days. It was also a proof of their obstinacy that they would give credit to no warnings until they were convinced by experience that they laid up in their houses nothing but a mass of corruption, for they were not persuaded to cease from their insatiable greediness until they had received their just punishment.

Now, although the case of the manna and the food of our ordinary nourishment is not altogether similar, the comparison holds to a certain extent. For it is lawful to keep our corn and wine stored in granaries and cellars only insofar as all should still truly ask God for their daily bread.

This will be the case if the rich do not greedily swallow up whatever they can gather; if they do not avariciously scrape up here and there; if they do not gorge themselves upon the hunger of the poor; if they do not, as far as it is in their power, withhold the blessing of God; in a word, if they do not immoderately accumulate large possessions but instead are liberal out of their present abundance, are not too anxious about the future, and are not troubled, if need be, that their wealth should suffer reduction; indeed, if they are ready to endure poverty, and do not glory in their abundance, but rest upon the paternal bounty of God.

And surely, we often see that what misers collect by theft, plunder, fraud, cruelty, trickery, or meanness often turns into corruption.

When he adds that after they saw that their excessive zeal profited them nothing, they submitted to the command, he implies that their obedience was not voluntary but forced from them, for fools are never wise except after adversity.¹⁸⁴

The melting of the manna when the sun grew hot was a stimulus to correct their idleness or laziness, for if the manna had remained intact throughout the whole day, they would not have been so focused on their duty. Therefore, by giving them only a short time for its collection, God urged them to diligence.

¹⁸⁴ “Sinon apres avoir este bien batus;” except after being well beaten. — Fr..