ומראש הררי קדם. וּמְבֹרֶכֶת מֵרֵאשִׁית בִּשּׁוּל הַפֵּרוֹת, שֶׁהֲרָרֶיהָ מַקְדִּימִין לְבַכֵּר בִּשּׁוּל פֵּרוֹתֵיהֶם. דָּ"אַ — מַגִּיד שֶׁקָּדְמָה בְּרִיאָתָן לִשְׁאָר הָרִים (שם): ומראש הררי קדם AND BY THE FIRST THINGS OF THE HILLS OF קדם (taken in the sense of: the hills priority) — the meaning is: and it is blessed through the earliest ripening of the fruits, because its hills are earliest (קדם, "prior") to bring their fruits to maturity. – Another explanation: this tells us that their creation (the creation of the hills in the territory of Joseph) was prior (קדם) to that of all other hills (Sifrei Devarim 353:4).
גבעות עולם. גְּבָעוֹת הָעוֹשׂוֹת פֵּרוֹת לְעוֹלָם וְאֵינָן פּוֹסְקוֹת מֵעֹצֶר הַגְּשָׁמִים: גבעות עולם [AND THROUGH THE PRECIOUS THINGS OF] THE EVERLASTING HILLS — i.e., of hills which everlastingly (עולם) produce fruit, and do not cease to do so through restraint of rain.