And the 27th mitzvah is that we are commanded to place lechem hapanim1 continually before G‑d [in the Communion Tent].

The source of this commandment is G‑d's statement2 (exalted be He), "You shall place lechem hapanim on this table before Me at all times."

You are already aware of the Torah's statements regarding placing new loaves each Sabbath,3 that there must be frankincense brought with it4 and that the Priest eats what was baked the previous Sabbath.5

The details of this mitzvah have been explained in the 11th chapter of Menachos.6