Kommentar zu Dewarim 12:20

כי ירחיב וגו׳ WHEN [THE LORD THY GOD] SHALL ENLARGE [YOUR BOUNDARY … AND YOU SHALL SAY, I WILL EAT FLESH … YOU MAY EAT FLESH] — The Torah teaches the proper rule of life — that one should not desire to eat flesh unless he lives amidst abundance and wealth (cf. Sifrei Devarim 75:5; Chullin 84a; see also Rashi on Leviticus 17:13).

WHEN THE ETERNAL THY G-D SHALL ENLARGE THY BORDER. The meaning of this “enlargement” is not like that which he stated, And if the Eternal thy G-d enlarge thy border⁵⁴Further, 19:8. [by giving you the land of the Kenites, Kenizzites, and Kadmonites] etc. then shalt thou add three cities more for thee,⁵⁵Ibid., Verse 9. for if it were, then meat of desire [meaning a meat meal prepared solely to satisfy the appetite rather than as a product of a peace-offering] would not have been permissible upon coming into the Land [but only after the enlargement of the border, an event that has yet to take place]. But there it is said, When the Eternal thy G-d shall cut off the nations, whose land the Eternal thy G-d giveth thee,⁵⁶Ibid., Verse 1. these being the seven nations that he mentions in all places,⁵⁷See above, 7:1. and then we are to separate three cities [as cities of refuge], and so Joshua did.⁵⁸Joshua 20:7-9. Afterwards he said, when the Eternal thy G-d enlarge thy border, as He hath sworn unto thy fathers,⁵⁴Further, 19:8. this being a reference to the ten nations that were given to Abraham.⁵⁹Genesis 15:19-21. Hence the command to establish an additional three cities of refuge becomes obligatory at the time when we shall have enlarged the border of our Land to include the territory of the remaining three of the ten nations promised to Abraham — the Kenites, Kenizzites, and Kadmonites. But here etc. But here he said, as He hath promised thee, meaning these [seven] nations whose land the Eternal your G-d gives you [now], thus indicating that immediately after they captured and apportioned the Land, a secular meal of meat became permitted to them.
Now, the purport of the expression If the place which the Eternal thy G-d shall choose to put His Name there be too far from thee⁶⁰Verse 21. is not that meat of desire [i.e., meat from an animal that has been slaughtered for food rather than as an offering] is permissible only at a distance from the Sanctuary, for if so, dwellers in Jerusalem would have been forbidden to eat meat of desire. Instead he [Moses] speaks to all Israel, saying to them that “when G-d will enlarge your border and not all of you will be dwelling around the Tabernacle as you are today in the wilderness, unconsecrated meat will be permitted, because it will be impossible for all of you to go from a distant place to the place that G-d will choose and slaughter sacrifices of peace-offerings as much as you wish to eat.”

כי ירחיב…את גבולך, "When G'd expands your borders etc." Seeing G'd had objected to the excessive craving for a meat-diet displayed by the Israelites in Numbers chapter 11 where we were told about thousands dying on that account, such a craving had been taboo ever since. Only meat which had first been hallowed as a sacrifice had been permitted to be eaten by the average Israelite during the last 38 years. At this point Moses justifies the new legislation which sanctions the desire to have a meat-diet by referring to the difficulty of making the meat first a sacrifice and having to travel to Jerusalem to do so. It is assumed that the craving will re-surface as a result of most people living a long way from Jerusalem. G'd specifically sanctions the desire to eat meat with the words: "you may eat meat in accordance with all the desire of your soul."