The Angel Rebukes Yehoshua for Neglecting Torah
In the middle of conquering Eretz Yisrael, an angel rebukes Yehoshua for neglecting Torah at night, and Yehoshua spends that night in deep Torah study.
The Navi (Yehoshua 5:13–14), as explained by the Gemara in Megillah (3a), tells us of a meeting between Yehoshua and an angel. An angel confronted Yehoshua: “Yesterday, you neglected to bring the afternoon korban tamid, and tonight, you have neglected the study of Torah.” Yehoshua asked him, “For which sin did you specifically come to rebuke me?” The angel answered, “I came now.” The angel was telling him that the primary purpose of his mission was to rebuke Yehoshua and the people for the sin they were committing at that time: failing to study today.
Rashi explains that during the day, Yehoshua and the nation were involved in a mitzvah and could not learn Torah. They were conquering Eretz Yisrael. However, since there was a cease in hostilities during the night, Bnei Yisrael should have taken the opportunity to learn Torah then. Yehoshua took the rebuke to heart, and that night he delved into deep Torah thought.