John Calvin Commentary Numbers 28:1

"And Jehovah spake unto Moses, saying," — Numbers 28:1 (ASV)

And the Lord spoke to Moses. Moses, being about to speak again of the “continual” sacrifice, premises that the people should diligently follow in their offerings whatever God has commanded; for by the word “observe,” (custodiendi,) not only diligence, but obedience is also expressed. But, so that they might more earnestly beware of every transgression, God calls either that which was usually placed daily on the table, or that which was added to the burnt offerings, His bread, as if He ate of it like humans do. It is indeed a difficult expression, but the unrefined nature of His ancient people obliged Him to speak in such a tangible way, so that, on the one hand, they might learn this rite to be acceptable to God, just as food is acceptable to humans; and, on the other, that they might strive to offer their sacrifices more purely and chastely.