Matthew Poole and continuators on Exodus 31:16

16 Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations for a perpetual covenant .

Or, shall keep the sabbath by observing or celebrating the sabbath, i. e. by observing or celebrating it, the antecedent being put for the relative, as is frequently done. So here is another most emphatical repetition to oblige us to the greater caution and diligence in this great duty, and to shew what stress God lays upon it, who hath therefore placed this in the midst of the commands of the Decalogue, as the heart which gives life and vigour to all the rest. Or it may be rendered thus, shall observe the day of rest to celebrate the sabbath, and so the phrase is like that, in the 4th. Command, Remember the sabbath day to keep it holy. So here, Observe the sabbath, i. e. watch its coming and approach, consider attentively the nature and use of it, and that not as a matter of idle speculation, but of serious practise, or so that you may do or celebrate the Sabbath, i. e. perform all the duties of it. Or thus, shall observe the sabbath, to make it a sabbath, or day of rest, and that no idle or carnal rest, but a rest, holy to the Lord, as it is called in the foregoing verse.

Or, by a perpetual covenant: or, it is a perpetual covenant, i. e. condition or part of that agreement made between me and them, they have solemnly covenanted or promised that they will do all that I commanded them, Exod. 24. 7, 8, among which this is a chief branch, and I have covenanted to bless and sanctify them in so doing. And this word perpetual, as also the word for ever being added to it in the next verse, may intimate that this hath a longer perpetuity than the c[illegible: 1+ letters]remonies, to which this phrase is sometimes ascribed, the rather because the reason of this perpetuity given in the next verse is such as hath its force not only till Christ, but even till the end of the World, and it is fit and just that men should retain this monument or memorial of the Worlds Creation even till its dissolution.