Who knows three hundred and seven?
?שבעה ושלוש מאות - מי יודע
In the spirit of the song "Echad - mi yodeya", please post interesting and significant Jewish facts about the number 307.
Check out mi-yodeya-series for the previous three hundred and six entries in this ongoing series.
Please include sources for your information wherever possible, as with all other answers on this site.