Yet Moses rebukes them and says to the sons of Reuben and to the sons of Gad: "Your brothers shall go to battle, and will you sit here? And why do you pervert the hearts of the sons of Israel, that they should not cross into the land which the Lord gives them?" And when he had rebuked them with words of this kind, "there came," he says, "to him the sons of Reuben and the sons of Gad and said: We shall build sheepfolds here for our sheep and for our cattle, and cities for our encumbrances, and we, armed, will advance in the first company before the sons of Israel, until we lead them into their own place." And promising these things they mollified Moses, so that he himself commended them to Joshua and to Eleazar. For thus it is written: "And Moses brought them to Eleazar the priest and to Joshua the son of Nun and to the leaders of the families of the tribes of Israel. And Moses said to them: If the sons of Reuben and the sons of Gad cross the Jordan with you, every one armed for battle before the Lord, and you obtain the land in your sight, you shall give them the land of Gilead for a possession." The name of "land," placed in the divine Scriptures, we find with diverse significations; and first indeed this land which we inhabit was not from the beginning called land, but "dry"; and after this, that which had first been called "dry" received the name of land; just as this visible heaven too was not from the beginning called heaven, but first "firmament," and afterward it was named also by the term "heaven." Yet in the beginning of creation God is said to have made heaven and earth, and afterward the dry, and afterward the firmament. But do you wish to know that "dry" is one thing in the Scriptures, and "land" another? Hear the prophet Haggai saying: "Yet once more I will shake heaven and earth and the sea and the dry land." You see how the prophet places "land" as one thing, "dry" as another. But also in many places of Scripture we find "land" named praiseworthily, but "dry" we do not easily read placed praiseworthily. For Adam too is thrust down into this place, as one culpable after his sin, which was named "dry." For before that he was not in the dry, but in the land; for paradise is not in the dry but in the land. But also what the Lord promises to the meek in the Gospel is not the dry, but the land. "Blessed," he says, "are the meek, for they shall inherit the land." And likewise in the Gospel the seed which gives fruit a hundredfold, sixtyfold, and thirtyfold is said to be land, not dry. And I think that there is a certain progress from the dry to coming to the land, just as there was also a certain progress that this land was called dry. For all of us, so long as we are unfruitful and bring forth no fruit of righteousness, none of chastity, none of piety, are dry. But if we begin to cultivate ourselves and to rouse our sluggish minds to the fruit of the virtues, we are made land out of dry, which, having received the seeds of the word of God, multiplies them with a glad harvest. There is, then, in the kingdom of God also a certain land which is promised to the meek, and a land which is named "of the living," and a land placed on high, concerning which the prophet says to the righteous man: "And he shall exalt you, that you may inherit the land." The inheritance, then, of this land, after it has gone forth from the Egypt of this world, the soul believing in God obtains; and in one place indeed those who lived under the law, but in another those who were dispensed through the faith and grace of Jesus Christ. Yet these who seem to be dispensed first and through Moses will not obtain the inheritance decreed to them until they too cross over with those whom Joshua dispenses, and fight with these against the enemies, and settle them in their seats, and thus they themselves shall obtain the inheritance which they merited with Moses as leader.
Source: HOMILIES ON NUMBERS 26.5