Upon a staff; either for the weight of it, considering the length of the way they were to carry it, or for the preservation of it whole and entire. In those eastern and southern countries there are vines and grapes of an extraordinary bigness, as Strabo and Pliny affirm.
Related Commentaries of Numbers 13:23
Numbers 13:23
23 And they came unto the brooka of Eshcol, and cut down from thence a branch with one cluster of grapes, and they bare it between two upon a staff; and they brought of the pomegranates, and of the figs.