Комментарий к Бамидбар 1:5

לראובן, Ibn Ezra writes that the reason why the members of the tribe of Reuven were counted first was because chronologically speaking, he was the first born of Yaakov’s children. Once all the children of Leah had been counted, the Torah switches to Joseph who was Rachel’s first born. Ephrayim was counted first, in accordance with the rank accorded him when Yaakov blessed him on his deathbed, switching hands in order to place his right hand on him. This was followed by counting the tribe of Dan, who was the senior son of the maidservants of Leah and Rachel. Then followed Asher, who was the leading tribe in the camp of Dan. He in turn was by followed by Naftali, who represented the senior son of Leah’s servant maid.

V. 5. Das ל־ in לשמעון ,לראובן usw. dürfte: für Reuben, für Simeon usw. bedeuten; der Stamm war durch sein Haupt vertreten.

לראובן אליצור בן שדיאור, “of Reuven, Elitzur son of Sh’deyur. He was mentioned first, as the original Reuven had been Yaakov’s firstborn son.”