In describing the self-destruction forces of envy and jealousy, our sages in the midrash relate a long dialogue between Moshe, of whom G-d had said that he was exceedingly humble, more so than any person on the face of the earth, and G-d. Moshe invoked various arguments to revoke the divine decree that he may not enter the promised land.
Moshe was told that each generation has its leader and the period of leadership is preordained. The predestined time had arrived for Joshua to assume the leadership role and there was no way that this could be delayed even for a single moment. To this Moshe responded, “Well, then let Joshua be the leader and I will be his disciple” and to this G-d agreed.
Joshua then entered the sanctuary and Moshe remain outside and observed the Divine cloud descending upon the sanctuary as it had so often done when G-d had spoken with him. When the cloud lifted and Joshua emerged, Moshe asked him, “What did G-d say to you?” Joshua responded, “All those forty years when G-d spoke privately to you, did I ever ask you what God had said to you?” (some explain that this is what Joshua was told to say to Moshe). Whereupon Moshe explained, “I would rather die one thousand deaths then experience one moment of envy!” and then surrendered his soul to G-d.
Moshe was ready to make whatever sacrifices G-d would request of him, in order that he be granted this single wish to set foot on the holy earth of Israel. Yet the awareness that he could continue to live only under circumstances that would arouse envy within him was enough to cause him to forgo the most fervent wish of his life.