"And you shall set upon the table shewbread before Me always"
(Exodus 25:30)

The ritual offering known as "shewbread" (lehem ha-panim) consisted of twelve loaves arranged in two rows. In the Tent of Meeting in the wilderness, the loaves were set out on a special table outside the curtain, and replaced once a week. When the Temple stood in Jerusalem, the shewbread was baked before the eve of the Sabbath and placed on a marble table in the entrance hall. Four priests arranged this table: two of them would bring in six loaves apiece, and two would each carry a censer of frankincense. Right before them came four other priests, who moved the loaves from the previous week to a gold table in the entrance hall and offered up the old incense. Now the old shewbread could be eaten by the priests, and a tradition in the Mishnah relates that this bread miraculously stayed fresh the entire week (M. Menahot 11).