Genesis 13:18

18.And Abram removed his tent (355) Here Moses relates that the holy man, animated by the renewed promise of Gods traversed the land with great courage as if by a look alone he could subdue it to himself. Thus we see how greatly the oracle had profited him: not that he had heard anything from the mouth of God to which he had been unaccustomed, but because he had obtained a medicine so seasonable and suitable to his present grief, that he rose with collected energy towards heaven. At length Moses records that the holy man, having, performed his circuit, returned to the oak, or valley of Mare, to dwell there. But, again, he commends his piety in raising an altar, and calling upon God. I have already frequently explained what this means: for he himself bore an altar in his heart; but seeing that the land was full of profane altars on which the Canaanites and other nations polluted the worship of God, Abram publicly professed that he worshipped the true God; and that not at random, but according to the method revealed to him by the word. Hence we infer, that the altar of which mention is made was not built rashly by his hand, but that it was consecrated by the same word of God.