Who knows three hundred twenty-one?
?אחד ועשרים ושלוש מאות - מי יודע
In the spirit of the song "Echad - mi yodeya", please post interesting and significant Jewish facts about the number 321.
Answers that only contain lazy gematria may be avoided like fire.
Check out mi-yodeya-series for the previous three hundred twenty entries in this ongoing series.
Please include sources for your information wherever possible, as with all other answers on this site.