Question
If Moses wrote down the Torah how could he write about his death?
Answer
The Talmud asks this question. Typically Talmudic, there are 2 opinions:
Yes, “with tears in his eyes” and No, Joshua did. To my knowledge there is no definitive conclusion there in the Talmud.
The Vilna Gaon found an ingenius resolution of these two mutually-exclusive opinions:
Moses wrote the Torah letter-by-letter. The last 12 verses he wrote out the letters but did not break them into words and verses. Joshua came along and completed that task. Hence, each tradition is correct: Moses wrote them, and Joshua wrote them.
Best,
Rabbi Seinfeld