Numbers 36:7

Overview - Numbers 36
The inconvenience of the inheritance of daughters is remedied by marrying in their own tribes,
lest the inheritance should be removed from the tribe.
10 The daughters of Zelophehad marry their father's brothers' sons.
Treasury of Scripture Knowledge

Numbers 36:7  (King James Version)
So shall not the inheritance of the children of Israel remove from tribe to tribe: for every one of the children of Israel shall keep himself to the inheritance of the tribe of his fathers.

for every one
That is, he shall not endeavour to obtain any part of the inheritance of another tribe by marrying an heiress.

keep himself
Hebrew cleave
9 ; 1 Kings 21:3