Midrash su Ezechiele 48:31

The schoolmen propounded a question: How was the land of Israel divided? Was it divided into twelve parts for twelve tribes (each tribe getting an equal share), or by the heads of the men? (Fol. 122) Come and listen! (Num. 26, 56) According as they are many or few [hence it was divided among the tribes and not by the heads of men]. And there is also a Baraitha: In the future the land of Israel will be divided among thirteen tribes, while in the past it was divided only among twelve; and it was also divided according to the value of money, and it was also divided only by lot and by the Urim and Tumim, as it is written (Ib. 55) By the decision of the lot. How so? Elazar was attired in the Urim and Tumim. Joshua and all Israel were standing by, and one urn containing the names of the tribes, and another urn containing the boundaries of the land, were placed there, and Elazar, influenced by the Divine Spirit, would say thus: "Zebulun will now come out from the urn, and with him the boundary of Achu." And then one of the tribe of Zebulon would put his hand into the urn and draw the name of his tribe, and then put his hand into another urn and draw Achu. And then again Elazar, influenced by the Divine Spirit, would say: "Now Naphtali will come, and with him the boundary Kmousar." And so it was with each tribe. However, the division in the future world will not be equal to to the division of land in this world, as in this world, usually, the lot of one is a field of grain, and of another, one of fruits; but in the world to come; everyone will have a share in the mountains, valleys and plains. As it is said (Ezek. 48, 31) The gates of Reuben, one, etc.; every one the same, and the Holy One, praised be He! will Himself assign the shares, as it is said (Ib. 29) And these are their allotted division, said the Lord Eternal. We see, then, that the Baraithat states that in the past the division was twelve parts to the twelve tribes. Hence it was divided among the tribes and not severally. The inference is sustained. The master said: "The land of Israel will in the future be divided among thirteen tribes." Who will be the thirteenth? R. Chisda said: "The prince of Israel will be the thirteenth, as it is written (Ib. 19) And they that serve the city out of all the tribes of Israel, shall fill it." R. Papa said to Abaye: "But perhaps this refers merely to public service?" And he answered: "This could not be borne in mind, for it is written (Ib. 21) And the residue shall be for the prince on, the one side and on the other of the holy offering, and of the possession of the city," etc. (Hence a real share is to be given to them by all tribes). And as to the value of money, as it is said, According as they are many or few. To what does this refer? Shall we assume that money was applied to the quality of the shares? Were they then so foolish as to take a bad field and money for it? But this refers only to quality of distance.