שְׁנֵ֥י הַמַּטּ֖וֹת וַחֲצִ֣י הַמַּטֶּ֑ה לָקְח֣וּ נַחֲלָתָ֗ם מֵעֵ֛בֶר לְיַרְדֵּ֥ן יְרֵח֖וֹ קֵ֥דְמָה מִזְרָֽחָה׃ (פ)
這兩個支派和半個支派，已經在耶利哥對面的約旦河東、朝著日出的東方，領受了他們的產業。」
Rashi
קדמה מזרחה — At the front of (קדם) the world which is the east; for the east side is called פנים, “the face" (equivalent to קדם, “front”), the west is called “behind”, and therefore the south is on the right and the north on the left (cf. Rashi on Exodus 27:13 and Note thereon).
Or HaChaim
שני המטות וחצי המטה לקחו נחלתם, The two and a half tribes took their inheritance, etc. The Torah wrote this verse to indicate that the inheritance of the half tribe of Menashe was part of the overall territory allocated by Moses to Reuven and Gad. Moses did not make separate boundaries for each of these tribes.
Rabbeinu Bahya
שני המטות וחצי המטה לקחו נחלתם מעבר לירדן קדמה מזרחה, “and the two and a half tribes took their inheritance on the far side of the river Jordan in a south-easterly direction.” This whole detail is repeated here to describe the exact area of their inheritance.