Musar על ברכות 109:3

לא תכבה . The reason that the Torah legislates that the fire on the altar should be kept going, never to go out (6,5), is to ensure that whenever our perennial accusers seek to be paid off by the life of some Jew or Jews there be an alternate fire handy to satisfy their demand to burn someone. The fire, in other words, acts as a "bribe" to Satan, much like the scapegoat on the Day of Atonement. Nowadays, when we have no altar, man's table fulfills the function of the altar. If we sit down to eat without at least saying some word of Torah during our meal, we may not have succeeded in extinguishing the fire of purgatory by keeping the fire on the substitute altar going. Inasmuch as תורה is a term used in connection with every category of sacrifice, all the destructive waters in the universe do not have the power to extinguish the flame of Torah, the flame of love.

You will now understand that if someone eats tissue from a living animal (one that is not completely dead) he may possibly be practicing a form of cannibalism, i.e. eating tissue of a fellow human being whose soul was re-incarnated in that animal. This is the mystical dimension of the Torah telling us : "Do not eat the soul with the flesh" (12,23). The entire legislation about domestic animals, free roaming beasts, or even birds which are "impure," is connected to the possibility that such animals harbor a spark of holiness by being host to a soul which had once inhabited a human body, a soul which had originated in the Celestial Spheres. It is irrelevant in this respect whether the soul in question originated in the "left" or the "right" side of the emanations. I have written more about the latter aspect in my commentary on פרשת שמיני. It is when the Israelites conduct themselves in a spirit of sanctity that the promise of Exodus 25,8: "They shall make a Sanctuary for Me and I will dwell among them," will be fulfilled. The people themselves are the Sanctuary within whom G–d promises to reside provided that they lead consecrated lives. Man's three major parts, i.e. the head, the heart and the bowels, correspond to the קדשי קדשים, Holy of Holies, the היכל, Sanctuary, and the חצר הקודש the Holy Courtyard surrounding the Temple, respectively. We have discussed this at length in פרשת תרומה. When a Jew consumes consecrated food he is considered as if he were the sacrifice offered on the Altar. Concerning this aspect of our lives, the Rabbis have said that nowadays our table serves as the altar.

השלחן. Our sages have said that in the absence of the Table in the Sanctuary, seeing that to-day there is no Sanctuary, our own individual tables are the instruments for our atonement (Chagigah 27) when they serve as vehicles to feed the poor, i.e. when one is hospitable. I have elaborated on this theme in my article on קדושה.