Exodus 16:20
Notwithstanding they hearkened not unto Moses; but some of them left of it until the morning, and it bred worms, and stank: and Moses was wroth with them. Notwithstanding they hearkened not unto Moses; but some of them left of it until the morning, and it bred worms, and stank: and Moses was wroth with them.
Exodus 16:20 belongs to the history of the children of Israel given in Exodus 13, 14, 15, and 16, when Jesus Christ enshrouded in the pillar of cloud led them and God by miracle gave manna in the wilderness as bread from heaven. The bread was a gift of mercy, yet its provision did not remove the need for cooperation, for participation in gathering it served moral discipline. The manna blessing was heaven's food shared also with strangers connected with Israel who met the stated conditions, including honoring God's Sabbath.
Some disobeyed Moses' instruction not to keep manna until morning, and what they left over bred worms and stank, and Moses was angry with them. The daily provision was to be gathered as needed each day, while the portion kept for the Sabbath did not spoil. That providing of food was part of an all-embracing education covering every habit of life, in which everything concerning well-being was the subject of divine care and came within divine law. Even in providing food God sought their highest good, and the manna was of a nature to promote physical, mental, and moral strength, so that notwithstanding the hardships of wilderness life there was not a feeble one in all their tribes.
The miraculous provision of manna confirms the validity of the seventh-day Sabbath established at creation and later proclaimed in the commandments. The manna miracle continually testified to the Sabbath commandment. The manna was sweet and nourishing when the portion God provided was accepted, but when in dissatisfaction it was kept, worms appeared in it, showing that discontent turns God's provision into a curse.
As food kept contrary to God's instruction spoiled overnight, breeding worms and becoming foul, so food stored up for the time of trouble will become unusable, and God's people must trust Him to provide for their needs then. Because the manna was to be gathered afresh rather than kept over, and what was left until morning spoiled, the need remains to seek fresh spiritual nourishment morning and evening and not be satisfied with past blessings.