And the LORD spake unto Moses, saying,

Jamieson-Fausset-Brown Bible Commentary

12-17. Verily my sabbaths ye shall keep-The reason for the fresh inculcation of the fourth commandment at this particular period was, that the great ardor and eagerness, with which all classes betook themselves to the construction of the tabernacle, exposed them to the temptation of encroaching on the sanctity of the appointed day of rest. They might suppose that the erection of the tabernacle was a sacred work, and that it would be a high merit, an acceptable tribute, to prosecute the undertaking without the interruption of a day's repose; and therefore the caution here given, at the commencement of the undertaking, was a seasonable admonition.

Matthew Henry's Concise Commentary

31:12-17 Orders were now given that a tabernacle should be set up for the service of God. But they must not think that the nature of the work, and the haste that was required, would justify them in working at it on sabbath days. The Hebrew word /shabath/ signifies rest, or ceasing from labour. The thing signified by the sabbath is that rest in glory which remains for the people of God; therefore the moral obligation of the sabbath must continue, till time is swallowed up in eternity.