The Fourth Commandment enjoins a day of _rest_ for man’s body. Jehovah, who “knoweth our frame,” who made us, and fully understands the capabilities of our brain, nerves and muscles, and who may with the profoundest reverence be termed, _The Great Physiologist_, has set apart one day in seven for bodily rest from labour. The body of Adam was stronger than ours. It knew no infirmity, was enfeebled by no disease; the labour of Paradise was comparatively light; and yet to Adam was given the rest of the seventh day. And to enforce this duty on our first parents, our merciful Creator not only sanctified the day, or made it a _holy_ and _sanctifying day_ for them, but rested himself as our example. There is no doubt that antediluvian believers kept the Sabbath, and they were as strong as we. We read of the observance of the Sabbath in the wilderness _before_ the law was given on Sinai, and Jehovah worked especial miracles on the manna to enable the children of Israel to rest on this holy day; for on the sixth he rained twice as much food from heaven as on any other morning, and on the seventh he preserved it from putrefaction, which always occurred on any other day, except the Sabbath, if the manna was kept until the morrow. God also said to these Israelites in the wilderness, before the law was given on Sinai, that the law of the Sabbath was to be observed “as a SIGN between himself” and his worshippers. We have reason to believe that these children of Abraham were quite as strong in nerve and muscle as we are, and we know that their labour was not very hard, for they had during their wanderings in the wilderness but few occupations, and yet they were commanded to rest on the seventh day. Some persons ask, Why did they rest on the _seventh_ day, and not on the _sixth_, the _eighth_, or the _tenth_? Our only answer to this question is, that God, “who knoweth our frame,” judged it to be best and ordained that it should be so. A man may ask me why the earth moves on her axis from the west to the east, and I confess that I cannot give any better answer than that it is the will of the all-wise Creator. I cannot give a reason why the centipede has so many feet. If any person asked whether eighty, or one hundred and one would not have been as well, I must leave the matter in the hands of God. I say, “it is the will of God,” and “God is merciful.” Ten thousand questions in physics might be put to me which I could only answer by saying, “God is wise,” “God is powerful,” “God is love,” “God is merciful, and has made the world and our corporeal frame what they are.”