וּלְגָ֣ד אָמַ֔ר בָּר֖וּךְ מַרְחִ֣יב גָּ֑ד כְּלָבִ֣יא שָׁכֵ֔ן וְטָרַ֥ף זְר֖וֹעַ אַף־קָדְקֹֽד׃
И о Гаде он сказал: да будет благословен Тот, кто увеличивает Гада; Он живет как львица, И держит руку, да, венец головы.
Rashi
ברוך מרחיב גד BLESSED BE HE THAT ENLARGES GAD — this teaches us that Gad’s territory extended far eastward (Sifrei Devarim 355:2).
Chizkuni
מרחיב גד, “Who enlarges Gad; Moses blesses him to whom G-d had given a large territory, suitable for raising sheep and cattle.
Da'at Zekenim
ברוך מרחיב גד, “blessed be he who enlarges the territory of the tribe of Gad.” Seeing that the ancestral land allotted to Gad was suitable for grazing rather than planting crops, this root is more appropriate for describing expansion. Compare also Hoseah 4,16: “עתה ירעם ה' ככבש בשמרחב, “now the Lord will graze him on the range like a sheep.”