Numbers 15:32

And the sons of Israel are in the wilderness, and they find a man gathering wood on the sabbath-day,

Exodus 35:2-3

Six days is work done, and on the seventh day there is to you a holy day, a sabbath of rest to Jehovah; any who doeth work in it is put to death;

And he saith unto them, 'It is that which Jehovah hath spoken of; a rest -- a holy sabbath to Jehovah -- is to-morrow; that which ye bake, bake; and that which ye boil, boil; and all that is over, let rest for yourselves in charge till the morning.'

Exodus 16:27-28

And it cometh to pass on the seventh day, some of the people have gone out to gather, and have not found.

Exodus 20:8-10

'Remember the Sabbath-day to sanctify it;

Exodus 31:14-15

and ye have kept the sabbath, for it is holy to you, he who is polluting it is certainly put to death -- for any who doeth work in it -- that person hath even been cut off from the midst of his people.