וְאִם־אֵ֣ין אַחִים֮ לְאָבִיו֒ וּנְתַתֶּ֣ם אֶת־נַחֲלָת֗וֹ לִשְׁאֵר֞וֹ הַקָּרֹ֥ב אֵלָ֛יו מִמִּשְׁפַּחְתּ֖וֹ וְיָרַ֣שׁ אֹתָ֑הּ וְֽהָ֨יְתָ֜ה לִבְנֵ֤י יִשְׂרָאֵל֙ לְחֻקַּ֣ת מִשְׁפָּ֔ט כַּאֲשֶׁ֛ר צִוָּ֥ה יְהוָ֖ה אֶת־מֹשֶֽׁה׃ (ס)
A gdyby nie miał braci ojciec jego, to oddacie jego udział krewnemu najbliższemu mu z rodziny jego, aby go odziedziczył; a niechaj będzie to dla synów Israela zasadniczém prawem, - jako rozkazał Wiekuisty Mojżeszowi!"
Rashi on Numbers
לשארו הקרוב אליו ממשפחתו TO HIS KIN THAT IS NEXT TO HIM OF HIS FAMILY — The term משפחה used in connection with inheritance denotes kinship only on the father’s side (Sifrei Bamidbar 134:3; Bava Batra 119b).
Ramban on Numbers
AND IT SHALL BE UNTO THE CHILDREN OF ISRAEL A STATUTE OF JUDGMENT. The meaning thereof is that this judgment should be for all [future] generations, and not only for now when they inherited the Land [hence the expression “a statute, i.e., a permanent one, for all the children of Israel in all future generations”].
Tur HaArokh
והיתה לבני ישראל לחוקת משפט, “This shall be for the Children of Israel as a decree of justice.” This will be a law from now on not only for the people that were about to enter the Holy Land.