Genèse 33:20

And he raised there an altar, and there he gave the tithes which he had set apart of all that he had before God, the God of Israel.

AND HE CALLED ‘LO’ (IT) E-IL-ELOKEI-ISRAEL. It does not mean that the altar was called “The G-d of Israel,” but because the Holy One, blessed be He, had been with him to deliver him, he named the altar in honor of the miracle so that the praise of the Holy One, blessed be He, would be recalled when people referred to the altar. Thus it would mean, “He Who is E-il is the G-d of me whose name is Israel.” Similarly we find in the case of Moses: And he called its [the altar’s] name Adonai-nissi. It is not that the altar was called by the Divine Name Adonai but rather that he named the altar in honor of the miracle so that the praise of the Holy One, blessed be He, might be mentioned: “G-d — He is my banner.” Our Rabbis expounded that the Holy One, blessed be He, called Jacob eil (a great and mighty man). [According to this, the verse should be interpreted as follows: “And the G-d of Israel called Jacob eil].” The words of the Torah are thus as a hammer splitting the rock into many different pieces, admitting many different explanations. I, however, make it my aim to render the plain sense of Scripture. All of this is the language of Rashi.
Now the words of the Rabbi [Rashi] are correct as regards the plain sense of Scripture. And the meaning of the word lo will then be [not “it,” which would refer to the altar, but “him,” which refers to Jacob], just as is the meaning of the same word in the verses: And his father called ‘lo’ (him) Benjamin; ‘Vekarei lecha’ (and thou shalt be called) The repairer of the breach.
Know that it was the custom in Israel that names be called which are indicative of the praises of G-d, such as Zuriel (G-d is my rock), Zurishaddai, 7:36. (The Almighty is my rock), for the one who calls that name declares that G-d is his rock and the Almighty is his rock. Likewise, Immanuel (G-d is with us). And so also the name of the Messiah, who will be called, The Eternal is our righteousness, and the name of Jerusalem will be, The Eternal is there. And so did they do with the names of the angels: Gabriel (G-d is my strength), Michael, 10:13. (Who is like unto G-d?), for because of their great power they proclaim with their very name that the strength belongs to G-d and who is like unto Him!
Onkelos however said: “And he worshipped on it before G-d, the G-d of Israel.” In that case the meaning of the word lo will …

א-ל אלו-הי ישראל, Who has saved me from Lavan as well as from Esau. The wording means that the same G’d Who had been the G’d of someone called Yaakov, continued in His role as the G’d of Yisrael. Just as people who are called Eliezer (G’s is my help) are also called Immanuel, seeing that the meaning is identical, so also the comparison between the G’d of Yaakov and the G’d of Yisrael. I believe this is the plain meaning of our verse.

ויקרא לו א-ל אלו-הי ישראל. When he prayed he referred to G’d as the G’d Who is the אלו-הי ישראל, corresponding to his vow that והיה ה' לי לאלו-הים, “G’d the merciful will be accepted by me as the G’d of Justice.” This standard of being judged by the attribute of Justice commenced only at the time when Yaakov had qualified for this level of righteousness having been given the additional name of Yisrael.

ויצב שם, considering that the Torah used the word ויצב instead of ויבן, he built, it is probable that this altar consisted of only one large lab of stone. He placed this stone in the appropriate position to serve as an altar upon which to offer his sacrifice.

ויקרא לו א-ל אלו-הי ישראל, he named the altar thus in commemoration of the fact that G’d had saved him while he was en route, and had sent an angel to accomplish that, and had also changed his name to Yisrael. It is possible that he placed the stone at the site where he had the nocturnal encounter with the angel. We find a parallel to this in Exodus 17,15 where Moses called the altar he had built ה' נסי, “G’d is my miracle,” in commemoration of the miracle G’d had performed for the Israelites enabling them to defeat the Amalekites. Another similar example of the name of G’d being linked to the salvation He brings to the Jewish people, albeit in the future, is found in Jeremiah 23,6, זה שמו אשר יקראו ה' צדקנו. A similar verse occurs in Jeremiah 33,17, whereas in Ezekiel 48,35 we found a city (the new Jerusalem) being named after an event (the redemption), the new name meaning: “the Lord is there.”