PURPORT

There are two kinds of brahmacaris. One may return home, marry and become a householder, whereas the other, known as brhad-vrata, takes a vow to remain a brahmacari perpetually. The brhad-vrata brahmacari does not return from the place of the spiritual master; he stays there, and later he directly takes sannyasa. Because Nabhaga did not return from the place of his spiritual master, his brothers thought that he had taken brhadvrata-brahmacarya. Therefore, they did not preserve his share, and when he returned they gave him their father as his share.