Where did Moshe come from?
Targum Yonasan: From the Beis-ha'Midrash. 1
Oznayim la'Torah: He came from close to the heaven, from where he sang the Shirah (Sifri). 2
Since when was Yehoshua a partner of Moshe Rabeinu?
Rashi: It was the Shabbos (the day that Moshe died) of 'D'yugazi' 1 , where the authority was taken away from Moshe and handed over to Yehoshua. 2
See Sifseei Chachamim and refer to 32:44:151:1.
Rashi: Moshe appointed a translator for Yehoshua - enabling him to Darshen in Moshe's lifetime, so that people should not say that Yehoshua was not important in Moshe's lifetime.
Bearing in mind that Moshe had already changed his name to Yehoshua, why does the Torah call him 'Hoshe'a'?
Rashi: To teach us that his new appointment did not go to his head and he remained as humble as he had been before.
Hadar Zekenim and Rosh: As long as he served Moshe, it was correct to call him by the name that Moshe called him. Here it calls him by his [original] name. 1 Everywhere [after this] he is called 'Yehoshua', the name to which he become accustomed.
Ha'amek Davar: Moshe recited Ha'azinu, and when he came to explain it, the Shechinah did not speak from his throat, so Yehoshua - through Moshe's Shelichus, helped him. He is called 'Hoshe'a' because he did not do so as Yehoshua, the Rebbi of Yisrael [after Moshe], but as Hoshe'a, Moshe's Talmid.
To mark the transition from Talmid of Moshe to leader of Yisrael. See Oznayim la'Torah.
QUESTIONS ON RASHI
Rashi writes that it was the Shabbos of 'D'yugazi'. What does that mean?
Riva: 'D'yu' means 'two'. There were two kingships
