אל תירא אברהם אנכי מגן לך שכרך הרבה מאד (טו:א)
After the war of the four kings, Avram has a divine dream in which Hashem told him, “Do not fear. I will be your shield and protector. Your reward shall be very great.” Why did Hashem tell Avram not to be afraid? This would make sense if Hashem told him this as encouragement before the war. However, Hashem told this to Avram after the war, which Avram had already won.
There are a few reasons why Avram was afraid. During the war of the four kings, Avram killed many people. Though they were mostly Reshaim, Avram was concerned that maybe Tzaddikim were killed in the war as well. There is a general rule, “When authority is given to the Destroyer, it does not distinguish between the Tzaddikim and the Reshaim.” Tzaddikim could die just as easily as the Reshaim. Avram was afraid that he would be punished for killing Tzaddikim. The Tzaddikim who fought in the war were probably forced to fight against their will. There is a law that a Jew cannot murder anybody even if his life is in danger. If a Tzaddik kills someone instead of getting killed himself, then only Hashem could kill him. This is why Avram was afraid. Avram thought he might have killed someone who he wasn’t supposed to kill.
There are some other reasons why Avram was afraid. Avram thought that the Reshaim may have had righteous children or that they may have converted to Judaism. So Avram was concerned about killing these people. Also, Avram thought that the families of those he killed would kill him and he would not be able to rely on a miracle to save him. Another reason is that Avram was uncomfortable of becoming rich through the Reshaim’s wealth. Finally, Avram feared that Shem (Ben Noach) would curse him for killing the people of the four kings because many of them were Shem’s descendents. Hashem tells Avram that he should not fear because He will protect him and make his reward great.
Before this vision that Avram received, he got visions only at night, but now he gets them during the day. There are ten words to describe Nevuah. The first two, which are the highest levels of Nevuah, are חזון (vision) and דיבור (speech). The Torah says, “God’s word came to Avram in a vision.” We see that the two highest levels of Nevuah are used here. This Nevuah experience was so great that Avram was afraid of it. Therefore, Hashem said to him not to be afraid. Hashem reassures Avram with a story. A man goes into the royal garden and saw a pile of thorns. He took them to use them to make a fire. As he was coming out of the gate, he saw the king coming and hid in order that he would not be punished for stealing from him. The king said to the man that he does not have to be afraid because he helped the king by removing the thorns. The king would have hired someone to do that so the man helped him out. The king told him that just like the man wanted to benefit himself by taking the thorns he gave benefit to the king and for that, the king will reward him.
Hashem tells Avram that the men were like thorns. They would not do much good for anyone so it was good that Avram killed them. For this, Avram would not be punished and he will even get a great reward. Hashem gave Avram a reward because of the Mitzva; “You shall destroy evil from your midst. (Devarim 13:1).”