Bilaam's War:

The Bais Yisroel zy"a said, "The war with Bilaam was very difficult. Bilaam wanted to uproot the entire nation of Klal Yisroel and destroy Yiddishkeit. This is why the navi exhorts us to remember what he planned. We have to always remember the war he waged against the Jewish people.” He quoted his father, the Sefas Emes zy "a, as saying that Bilaam was a young man. He was only 32 years old. He also was blind and he had a limp. Klal Yisroel didn't take him seriously. They didn't realize how much he wanted to harm them, and they couldn't imagine that he had the ability to hurt them at all. Therefore, the navi tells us to remember how even a young, crippled person can hurt us. This is a lesson to us to be careful around all enemies. We must not underestimate any of our haters because we don't know what they are capable of. We can also learn from this how much we have to be on guard from the yeitzer hara, and how we always must daven to Hashem to have the strength to overcome it.