On the east side the border was the Jordan. These were the borders around the inheritance of the clans of the tribe of Benjamin.
KJV
And Jordan was the border of it on the east side. This [was] the inheritance of the children of Benjamin, by the coasts thereof round about, according to their families.
ASV
And the Jordan was the border of it on the east quarter. This was the inheritance of the children of Benjamin, by the borders thereof round about, according to their families.