31:15 seventh is the sabbath. Breaking God’s rest day was defined by Him as a capital crime among His chosen people, and this at least shows all people how vital its observance is to Him. As far as Israel was concerned, it was to be observed perpetually. Since its use long antedates the calling of Israel, it should actually be regarded as a perpetual reminder to all people of the preeminent importance God placed on the fact of His completed work of creation, and His abhorrence of any religion (e.g., evolutionism) or any practice which denied or trivialized this foundational doctrine.
31:17 in six days. Here is repeated the formula of Exodus 20:8-11, making it undeniable that the six creation “days” were literal days. God even wrote it down with His own finger on a table of stone (Exodus 31:18). All Scripture is divinely inspired, but this was divinely inscribed! To attempt to stretch these days into ages of evolution would destroy the very basis of God’s supremely important day of rest and commemoration. That His work of creation is not still continuing, as theistic evolutionists allege, but was completed in the six days, is not only indicated by the past tense (“God rested,” rather than “is resting”) but also by the fact that He “was refreshed,” as He contemplated the marvelous universe He had created and made.