They had to marry sons of Manasseh so that the inherited property would remain with the same tribe. ​ — Num.
فَقَدْ وَجَبَ أَنْ يَتَزَوَّجْنَ رِجَالًا مِنْ بَنِي مَنَسَّى لِكَيْ يَبْقَى ٱلْمِلْكُ ٱلْمَوْرُوثُ فِي نَفْسِ ٱلسِّبْطِ .‏ —‏ عد ٢٧ :‏ ١ -‏ ٨ ؛‏ ٣٦ :‏ ٦ -‏ ٨‏ .‏