Tanna of the first generation (first century); lived in Jerusalem. According to R. Nathan, he was one of the three most renowned "dayyane gezelot" (criminal judges) in Jerusalem (Ket. 105a; Yer. Ket. 13:1; Frankel, "Darke ha-Mishnah," p. 63). He was one of the seven great contemporaries of Johanan b. Zakkai who had survived the destruction of Jerusalem by the Romans (Grätz, "Gesch." 4:20) and who probably became members of the Sanhedrin at Jabneh.
Only six halakot of Nahum's have been preserved in the Talmud, three of which were said not to have been recognized ("nishtaḳa 'ha-dabor"; 'Ab. Zarah 7). Some, however, attribute to him four other and anonymous halakot (Weiss, "Dor," 1:182).
The opposition to the decisions of Nahum, according to the view of a later amora, seems to have been due to the dislike of the Palestinians to scholars of other countries.