Positive commandment · Mitzvat Aseh #27 of 613
To arrange bread and frankincense before G-d [in the Temple] on every Shabbat
לְהַסְדִּיר לֶחֶם וּלְבוֹנָה לִפְנֵי ה' בְּכָל שַׁבָּת
The verse · Shemot 25:30
וְנָתַתָּ עַל־הַשֻּׁלְחָן לֶחֶם פָּנִים לְפָנַי תָּמִיד
“And thou shalt set upon the table showbread before me always.”
The Rambam’s words
To arrange bread and frankincense before G-d [in the Temple] on every Shabbat, as [Exodus 25:30] states: "And you shall place the showbread on the table."
לְהַסְדִּיר לֶחֶם וּלְבוֹנָה לִפְנֵי ה' בְּכָל שַׁבָּת, שֶׁנֶּאֱמָר: "וְנָתַתָּ עַל הַשֻׁלְחָן לֶחֶם פָּנִים" (שמות כה, ל).
Why · Sefer HaChinuch #97
Arranging the bread of display and the frankincense
“It is from the roots of this commandment that G-d, blessed be He, commanded us the constant commandment of the bread, on account that through it a man lives; and as a result, [the commandment] is needed by him for blessing to always be found in [his bread].”
Who & when
“And [it] is practiced at the time of the Temple by male priests, as the service is theirs, and not women’s.”
Where in the Mishneh Torah
Hilchot Daily Offerings and Additional Offerings הלכות תמידים ומוספין