וַיְצַ֞ו אֶת־יְהוֹשֻׁ֣עַ בִּן־נ֗וּן וַיֹּאמֶר֮ חֲזַ֣ק וֶֽאֱמָץ֒ כִּ֣י אַתָּ֗ה תָּבִיא֙ אֶת־בְּנֵ֣י יִשְׂרָאֵ֔ל אֶל־הָאָ֖רֶץ אֲשֶׁר־נִשְׁבַּ֣עְתִּי לָהֶ֑ם וְאָנֹכִ֖י אֶֽהְיֶ֥ה עִמָּֽךְ׃
I ustanowił Jehoszuę, syna Nuna, i rzekł: "Bądź silnym i wytrwałym, gdyż ty wprowadzisz synów Israela do ziemi, którą im zaprzysiągłem, a Ja będę z tobą!"
Rashi
ויצו את יהושע בן נון AND HE COMMANDED JOSHUA THE SON OF NUN — This has to be connected with v. 14 above, and it refers to the Shechinah (to God; “He commanded” means “God commanded”), as it distinctly states here “[for thou shalt bring the children of Israel] into the land which “I” swore unto them, [and “I” will be with thee]”.
Chizkuni
ויצו את יהושע, “He commanded Joshua;” The Lord commanded him (not Moses) These words refer to verse 14 in our chapter.
Ramban
AND HE COMMANDED JOSHUA THE SON OF NUN. “This [pronoun ‘He’] refers to the Divine Presence [mentioned] above45I.e., Verse 14: And the Eternal said unto Moses … as it is explained [here], into the Land which I swore unto them; and I will be with thee.” This is Rashi’s language. He has explained it well. And in the opinion of Rabbi Abraham ibn Ezra:46Found in Ibn Ezra on Verse 15. “And he commanded Joshua — that is, Moses [commanded] by order of G-d, and therefore he said, into the Land which I swore unto them.” Similarly we find that Moses said, And I will give the rain of your Land in its season.47Above, 11:14. So also, And I will give grass in thy fields for thy cattle.48Ibid., Verse 15. Likewise, that ye might know that I am the Eternal your G-d.49Above, 29:5. And so also, The Eternal will send upon thee the scantiness etc. because of the evil doings, whereby thou hast forsaken Me.50Above, 28:20. I have already discussed this.51See above, 5:12.