Rashi on Deuteronomy 33:23/רש"י על דברים ל״ג:כ״ג

1שבע רצון [NAPHTALI IS] SATISFIED WITH DESIRE — it means that his land was full of everything that its inhabitants could desire.

2ים ודרום ירשה POSSESS THOU THE WEST (lit., the sea) AND THE SOUTH — The sea of Kinneret fell to his portion and he received on its south a ropes length of fishing-coast for spreading out his nets and meshes (Bava Kamma 81:2; cf. Sifrei Devarim 355:17).

3ירשה — This word it a form of the imperative, as is the verb in (Deuteronomy 1:21), “Go up and take possession (רַשׁ)”. The accent that is penultimate, on the ר, proves this. Just as in the case of the ordinary imperative forms of the verbs, סלח, ידע, לקח, שמע, when one adds a ה at the end the accent will be penultimate, viz., ,סלחה, ידעה, לקחה, שמעה, here also ירשה is an imperative form. In the Massora Magna we find it included in an alphabetical register of imperative forms the accent of which is on the penultima (next to the last syllable).