Commentaire sur La Genèse 13:4

אשר עשה שם בראשונה [UNTO THE PLACE OF THE ALTAR] WHICH HE HAD MADE THERE AT THE FIRST and WHERE ABRAM HAD CALLED [UPON THE NAME OF THE LORD] (that is, ויקרא does not introduce a further action of Abram done at that time, but refers to a former one when he had called upon the Name of the Lord); but it may also be explained that it means that Abram now called there upon the Name of the Lord.

אל מקום המזבח, the Torah details further that Avram did not only return to the mountainous region of which we had been told in 12,8 but that he returned to exactly the place where he had prayed previously. We are to learn from this how important it is for a person to appoint a definitive spot from where to offer his prayers on a regular basis. It is easier to concentrate when one is in familiar surroundings. Now that he had returned to this altar, Avram preached a second time in the name of the Lord, [no doubt telling people of his miraculous escape from Egypt, laden with new riches. Ed.]

And where “Avram called...” Rashi is answering the question: Since Avraham already made an altar there and called in the Name of Hashem, why does it tell us here [again], “And there Avram called...”? Thus Rashi explains that the verse is informing us where he went: to the place from where he had already called in the Name of Hashem.