Numbers 15:32

And while the sons of Israel were in the wilderness, they found a man that gathered firewood upon the sabbath day.

Exodus 35:2-3

Six days shall work be done, but the seventh day shall be holy unto you, a sabbath of rest to the LORD; whoever does work therein shall die.

And he said unto them, This is what the LORD has said, Tomorrow is the holy sabbath of rest unto the LORD; bake that which ye will bake today and cook what ye will cook; and that which remains over lay up for you to be kept until the morning.

Exodus 16:27-28

And it came to pass that some of the people went out on the seventh day to gather, and they found none.

Exodus 20:8-10

Thou shalt remember the sabbath day, to sanctify it.

Exodus 31:14-15

Ye shall keep the sabbath therefore; for it is holy unto you; those that defile it shall surely be put to death; for whoever does any work therein, that soul shall be cut off from among his people.