Exodus 34:21

Six days thou shalt work, but on the seventh day thou shalt rest: in earing time and in harvest thou shalt rest.

The verse belongs to the words of the covenant, the Ten Commandments. The Lord Himself wrote those words upon the two tables of stone that Moses had prepared and carried to the summit. This took place during his second forty days and nights on the mount, when he was alone with God, permitted no man to go up with him, and was miraculously sustained the whole time in communion with God.

The verse commands work on six days and rest on the seventh day. It specifies the very seventh day God appointed and sanctified, and it requires keeping His Ten Commandments and keeping the Sabbath. It therefore leaves no excuse for becoming careless and indifferent and thinking it does not matter what day is kept, and no excuse for keeping the first day of the week.

The verse requires rest even in earing or plowing time and in harvest. Those are the busiest seasons of the year, when work is most urgent and fruits and grains must be secured. God gave this specific direction so that pressure to secure crops would not lead to Sabbath work. Seasonal labor gives no excuse for Sabbathbreaking, and in no case is personal or one's own work to be done on the Sabbath or holy time to be trespassed upon, for the Sabbath belongs to God.

Obedience to the verse is part of faithful service. Temporal blessings come from the bountiful hand of the Creator. He increases them with faithfulness and diminishes or withdraws them with unfaithfulness in His service. Using holy time for personal work therefore brings loss rather than gain.