And Naaman said, shall there not then, I pray thee, be given to thy servant two mules' burden of earth..... Not that he desired of Elisha that he would suffer his servant Gehazi to receive a present as much as two mules could carry; but inasmuch as the prophet refused a present from him, his servant, he asks a favour of him, that he would permit him to take with him, out of the land of Israel, as much earth two mules could carry, that is, to make an altar of earth, as the next words indicate: but as he might have this any where without the prophet's leave, some Jewish writers think he requested it from his own house, and from the place his feet trod on, as conceiving in a superstitious way that there was a sort of holiness in it; or however, that wheresoever he had it, if with the prophet's leave, a blessing would go with it, or that would be a sort of a consecration of it; and having an altar made of the earth of this land, would show that he was in the faith of the same God, and performed the same worship to him Israel did:for thy servant will henceforth offer neither burnt offering nor sacrifice unto other gods, but unto the Lord: hence the Jews say, he became a proselyte of righteousness , embraced the true religion, and the worship of the true God, according to the laws given to Israel; and the following words, rightly understood, confirm the same.
Ben Gersom & Abarbinel in loc. Shalshalet Hakabala, fol. 11.