וַיֵּשְׁבוּ֮ לֶֽאֱכׇל־לֶ֒חֶם֒ וַיִּשְׂא֤וּ עֵֽינֵיהֶם֙ וַיִּרְא֔וּ וְהִנֵּה֙ אֹרְחַ֣ת יִשְׁמְעֵאלִ֔ים בָּאָ֖ה מִגִּלְעָ֑ד וּגְמַלֵּיהֶ֣ם נֹֽשְׂאִ֗ים נְכֹאת֙ וּצְרִ֣י וָלֹ֔ט הוֹלְכִ֖ים לְהוֹרִ֥יד מִצְרָֽיְמָה׃
Then they sat down to a meal.* Looking up, they saw a caravan of Ishmaelites coming from Gilead, their camels bearing gum, balm, and ladanum to be taken to Egypt.
*Aside from those who tended the flock, including Reuben; cf. Bekhor Shor.
(The above rendering—and footnote—come from the RJPS translation, an adaptation of the NJPS translation. Before accounting for this rendering, I will analyze the plain sense of the Hebrew text.)
The new footnote (whose insertion is consistent with the NJPS and RJPS practice of clarifying personal references) reflects the persuasive explication in Richard C. Steiner, “Contradictions, Culture Gaps, and Narrative Gaps in the Joseph Story,” Journal of Biblical Literature 139, No. 3 (2020): 439–58.
The main line of the narrative explicitly tracks the actions of the majority of brothers—but not all of them. As Steiner argues, it went without saying that somebody needed to be tending the flock while most of them ate. That was a basic fact about shepherding that the ancient audience would have known and taken into account.
Furthermore, recognizing this fact is vital for narrative coherence: it explains quite naturally why Reuben is absent when Joseph is sold off (vv. 25–28), and thus why he “returns” to the pit and is astonished to find Joseph gone (vv. 29–30).