With Parashat Vayechi we conclude Chumash Bereishit. We part from both Yaakov Avinu and Yosef HaTzaddik: this is truly the closing of a circle.

That circle begins in Parashat Vayetze, at Yosef's birth. Immediately after, Yaakov says to Lavan:

What is special about Yosef that he is the one able to overcome Esav? Why him, and not Reuven, Shimon, or the other brothers? The answer is in our parasha: it is Shalom, peace.

After burying Yaakov in the Land of Canaan and returning to Egypt, the Torah tells us:

First clue: the stop at the pit. The Midrash relates that on the way back, the caravan traveled the route by which Yosef had been taken to Egypt. Near Dotan, Yosef halts the convoy, descends, approaches the pit, looks left and right, and reflects.

The brothers think: 'It's over for us! He is looking at the place where we threw him; he will take revenge.'

Second clue: the mourning meal. Back at the palace, during the seudat havra'ah, Yosef does not sit with them but remains apart. The brothers recall that he had once seated them separately from the Egyptians: 'Again he sets us apart; he is preparing his revenge.'

In panic, the brothers come to tell Yosef:

Yet nowhere in the entire Torah do we find that Yaakov gave such a command. From here our Sages derive: 'Mutar leshanot mipnei hashalom' — it is permitted to alter the truth for the sake of peace.

Yosef's reaction? He weeps. For he realizes something terrible: Yaakov never knew the story of the sale. Yosef never told him, nor did the brothers, nor even Binyamin.

Why the stop at the pit? Yosef answers:

Yosef looked at the pit once full of snakes and scorpions and thanked Hashem for saving him.

Why not sit with them? Yosef explains:

From this whole narrative emerges the phrase that summarizes the entire book:

Immediately after, we read: 'These are the names of the children of Israel… and they were fruitful and multiplied.' The Book of Bereishit ends with Shalom: the brothers 'lie' for peace, and Yosef ensures the entire saga concludes in peace.

Now we understand why Yosef is specifically 'the Satan of Esav':

Esav shares the same gematria as Shalom! His Sitra Achra is against peace: he waves the banner of peace yet represents its opposite. Only one whose entire essence is built on true Shalom can answer him — and that is Yosef.

Follow Bereishit from beginning to end: it is nothing but conflicts — Adam and the serpent, Cain and Hevel, Yishmael and Yitzchak, Yaakov and Esav, the sale of Yosef. The whole book is wars between brothers.

The Hebrew vowels correspond to the ten Sefirot, each linked to a 'shepherd.' Yosef is associated with Yesod, whose nikkud is the Shuruk — the Vav with a dot inside it: וּ.

This is why, in the final blessing of the Amidah, the Divine Name is vocalized with the Shuruk:

This is Yosef's sefira, for Yesod connects Heaven and Earth — and that connection is Shalom. All our prayers aim to bind Heaven and Earth, so that Hashem, 'עֹשֶׂה שָׁלוֹם בִּמְרוֹמָיו,' may make peace upon us and upon all Israel.