Where's the beef?

Towards the time when the Israelites were about to enter the Land of Israel, G-d told them “When the Lord, your God, expands your boundary, as He has spoken to you, and you say, "I will eat meat," because your soul desires to eat meat, you may eat meat, according to every desire of your soul.”
One opinion holds that through this, Hashem allowed them to eat flesh as they desired. Up until that point, unconsecrated meat had been forbidden for consumption unless it was brought up on the altar. This is perhaps why the consumption of ordinary meat became possible once they entered the land.
This issue isn’t easily understood. We know that in the desert, the Jewish people were on a very high spiritual level. They were completely freed from all material concerns and thus were able to devote their entire existence to serve Hashem. This situation stands in stark contrast to what they encountered in the Land of Israel where they had to lead a material existence with all its attendant issues. So why is it that only when they had descended from the spiritual high of the desert were they permitted to eat meat as they desired?
The reason is that in the desert they didn’t possess the tools and power to refine and elevate worldly matters. During that time ( in the desert) they were requested to shield themselves from the world and even their sustenance was spiritual – the Manna. It is only when the Jews entered the Holy Land did they acuire the ability to refine the world. This was the beginning of the avoida ha-birurim – a rectification and refining of the world’s materiality to create from it a dwelling for the Divine Presence. It is at that time that they received the ability to elevate and sanctify “basar taiva” – unconsecrated meat and that’s when G-d allowed them to eat it.
How is unconsecrated meat elevated? The next paragraph declares “be strong not to eat the blood, for the blood is the soul”. Blood symbolizes enthusiasm and desire, and the Torah declares – it’s ok to eat meat but the accompanying desire (blood) is forbidden. The blood is only to be used for sprinkling the Altar, in other words, that enthusiasm must be reserved for holy purposes only.
But how do we handle material desires? Torah explains “you shall spill it on the ground, like water”. A Jew ideally should not have any material desires for their own sake, everything that is done needs to be done Le’shaim Shamaim in the service of Hashem following the precept “in all your ways you should know Him”. The truth is that even when a Jew does desire something material, that desire ultimately stems from his soul which wants to elevate that particular part of materiality. When such an attitude is adopted, not only material desires are not an obstacle, on the contrary, they aid in elevating the world and making it a dwelling place for G-d.
Excerpted from “Shulchan Shabbat” based on Likutei Sichos vol.4., p 1108.