Deuteronómio 12:20 Halajá: Peninei Halakhah, Kashrut, Mishneh Torah, Human Dispositions & Mishneh Torah, Kings and Wars

Together with the permission of eating meat that is not offered in the Temple there is the prohibition of eating blood, as it is written (Deut. 12:20-23) ... that is to say, blood has a specific mission, which is to support the soul of the living animal, and therefore even though the Torah permitted us to eat meat, it did not permit us to eat blood.

A disciple of the wise adjusts his affairs judiciously: he eats, drinks and supports his family within his capital and material success; but he should not overburden himself more than necessary. The wise men command a worldly custom that a man should not eat meat save when craving it, even as it is said: "Because thy soul desireth to eat flesh" (Deut. 12.20). It is enough for a healthy person to eat meat from Friday night to Friday night. If, however, he be rich enough to eat meat daily he may eat. The wise men commanded and said: "Ever let a man eat less than what his financial means allow, dress within his means, but honor his wife and children with more than his means allow".¹³Hullin, 84b. C.

Even in the section regarding the cities of refuge it says, “If the Lord your G-d shall enlarge your borders…and shall add for you another three cities more…” (Deut. 12:20, Deut. 19:8-9). This actually never took place¹²³Since there were never nine, but at most six Cities of Refuge. The additional three must therefore be prophetic., and the Holy One Blessed be He never commands for nothing. However, from the words of the Prophets this matter does not need a proof, since all the Books are full of this matter.