If your brother does not live near you, or if you do not know who he is, you are to take the animal home to remain with you until your brother comes seeking it; then you can return it to him.
KJV
And if thy brother [be] not nigh unto thee, or if thou know him not, then thou shalt bring it unto thine own house, and it shall be with thee until thy brother seek after it, and thou shalt restore it to him again.
ASV
And if thy brother be not nigh unto thee, or if thou know him not, then thou shalt bring it home to thy house, and it shall be with thee until thy brother seek after it, and thou shalt restore it to him.