MIDRASH VA-YISSA'U (Heb. מִדְרַשׁ וַיִסָּעוּ), a medieval Midrash in Hebrew about the legendary wars of Jacob and his sons. The name derives from the first word of Genesis 35:5, with which the Midrash opens. The original name of the work is probably "The Book of Wars of the Sons of Jacob," a name which is preserved in Naḥmanides' commentary on the Book of Genesis (to Gen. 34:13), the earliest reference to the existence of the legend. The small book contains three chapters. The first describes a war of Jacob and his sons against the army of Ninevites, who came to Palestine to subdue the whole world. Characteristic of this chapter are exaggerations which are lacking in the two other chapters, a style possibly influenced by the Book of Josippon. This chapter does not appear in some manuscripts, although two of them consist of it only, which indicates that it was possibly a later addition to the Midrash. The second chapter describes the wars of the sons of Jacob against the Amorite kings seven years after Jacob and his family withdrew from Shechem (Gen. 35:5) because of the defilement of Dinah and the events which followed. The story of the victory over the Amorite kings is opposed to that of the biblical narrative, where Jacob fears that he will be outnumbered and destroyed. However, the story of the victory is hinted at in Genesis 48:22, a verse which is quoted to this effect in the Midrash. The third chapter describes the war between Jacob and his sons and Esau and his sons, in which Esau is killed by Jacob and Esau's descendants become tributary to Jacob's family.
The medieval Hebrew book (with the exception of the first chapter) is a free translation from Greek (or Latin) of an old Jewish (Hebrew or Aramaic) text from the time of the Second Temple, a text which was also used by the authors of the Book of Jubilees and the Testaments of the Patriarchs: the wars against the Amorites are narrated in the Testament of Judah, chapters 3–7, and in an abbreviated form in Jubilees 34:1–9; and a parallel narrative to the war against Esau and his sons is preserved in Jubilees 37 and 38:1–14, and in an abbreviated form, in the Testament of Judah, chapter 9. The medieval Midrash Va-Yissa'u is of great importance for a reconstruction of the original ancient Jewish text. The ancient text, which was used by the Book of Jubilees and the extant Testament of Judah, and is the basis of chapters 2–3 of Midrash Va-Yissa'u, could have been a separate work. It seems more probable, however, that the common source of all three works, in their description of the war of Jacob and his sons against the Amorite kings and against Esau, was an older and more expanded form of the Testament of Judah than its extant form in the Testament of the Patriarchs, a situation similar to that of the Testament of *Levi and the Testament of *Naphtali. Some scholars see in the description of the wars against the Amorites and Esau a tendentious projection into the biblical past of the wars of John Hyrcanus against the Samaritans and Edomites, the descendants of Esau, and a historical justification of these wars. Midrash Va-Yissa'u was used, expanded, and rewritten in the medieval Sefer ha-Yashar ("Book of Jashar"). A critical edition was published with an introduction by J.Z. Lauterbach in Abhandlungen zur Erinnerung an H.P. Chajes (1933, Heb. pt. 205–22).
S. Klein, in: ZDPV, 57 (1934), 7–27; A. Jellinek, Beit ha-Midrash, 3 (19382), ix–xiv, 1–5; R.H. Charles (ed.), The Greek Versions of the Testaments of the Twelve Patriarchs (1908), li, 235–8; idem (ed.), The Testaments of the Twelve Patriarchs (1908), lxv, 69–79; idem (ed.), The Book of Jubilees (1902), 200–4, 214–21; Ginzberg, Legends, 5 (1925), 315f., 321f.; Y.M. Grintz, Perakim be-Toledot Bayit Sheni (1969), 105f., n. 2.