Va’ethanan 

ואתחנן

Although his judgment was decreed and sealed, Moses continued to pray and implore. Because the decree that Moses would not enter the land was based specifically on the letter of the law, he requested entry as a gift from God. 

Even though it was decreed upon Moses not to enter the land, he did not stop praying, as it is stated: “I pleaded with the Lord” (Deuteronomy 3:23). It does not say “I prayed,” but “I pleaded [va’ethanan],” an expression indicating [requesting something for] free [hinam].

You find that when Moses ascended up to the Holy One, blessed be He, on Mount Sinai to receive the Torah, he began by saying: “Show me, please, Your glory” (Exodus 33:18), and the Holy One, blessed be He, showed him everything that is in the world above, and the rewards of each and every individual. Moses said to Him: This treasure, whose is it? God said: It belongs to those who engage in Torah study. And this treasure, whose is it? God said: It belongs to those who perform acts of charity. And whose is this? God said: It belongs to those who observe My mitzvot. And whose is this? God said: It belongs to those whose actions are proper.  

Then God showed him a great treasure. Moses said to Him: Master of the Universe, whose is this? The Holy One, blessed be He, said to him: This belongs to one who has performed no good deeds, but I give him a reward from this treasure for nothing; as it is stated: “I will favor whom I will favor [ahon]” (Exodus 33:19), meaning: I give him from the treasure for nothing [hinam].

When Moses came to request from the Holy One, blessed be He, to allow him to enter the Land of Israel, he was pleading, but the Holy One, blessed be He, would not accept his plea. Moses said to Him: Master of the Universe, if I have deeds to my credit, grant it to me for my deeds, and if I have no deeds and no merit, give me from that treasure that I saw that is given for nothing. 

Rabbi Hoshaya said: At that moment, the Holy One, blessed be He, said: It is better that a dangerous snake enter your house, and not a person. If I hadn’t shown you all My treasures, you would not know what I have. <source>(Devarim Rabba [Lieberman], Va’ethanan) </source>