Midrasch zu Dewarim 19:14

(Fol. 85a) R. Chiya b. Abba said: "What is meant by the passage (Deut. 19, 14.) Thou shalt not remove thy neighbor's landmark, which the people of old have set, i.e, Thou shalt not go beyond what is limited by those of old." What have those of old limited? R. Samuel b. Nachmeini, in the name of R. Jochanan, said: "It is WTitten (Gen. 36, 20.) These are the sons of Seir the Chorite, who inhabited the land. Did the rest of mankind inhabit heaven? But [it means that] they were experts in agriculture. 'This measure [of ground],' they would say, ' is adequate for [the planting of] olive trees; this measure of ground for wines, and this measure for dates.'" What does V'chori mean? This means they used to smell the earth. And what means Ve'chiri? R. Papa said; "They tasted the earth [to know for what it would be adequate] as a serpent does." R. Acha b. Jacob said: "Chori means they became freed of their wealth [because they lost it]."

(Devarim 19:14) "You shall not move back (into his own land, thus broadening your own), the boundary marker of your neighbor." Is it not already written (Vayikra 19:13) "You shall not rob"? What, then, is the intent of the above? We are hereby taught that one who removes his neighbor's boundary marker transgresses two negative commandments.