As בני ישראל travelled towards ארץ ישראל, they passed through נ ח ל א ר נוֹן, a deep, narrow valley. The א מוֹר י ים hid in caves atop one of the mountains above the valley, planning to bombard בני ישראל with arrows and stones as they passed through.
When בני ישראל arrived, Hashem caused the top of one mountain to move against the other, crushing and killing the אמוריים who were there, thus saving בני ישראל.
Hashem wanted בני ישראל to know about the miracle that He had done for them and what they had been saved from, so He caused the water from the well that travelled with בני ישראל in the desert to wash up limbs of the אמוריים, and caused it to flow around the camp for בני ישראל to see.
When בני ישראל saw this, and realized what had happened, they sang a special שירה, a song of thanks to Hashem.
Question
Although there were many miracles that Hashem did for בני ישראל while they were in the מ ד ב ר, we only find that they sang שירה for this miracle, and at קריעת ים סוף. What was unique about these two miracles?
Answer
By קריעת ים סוף we find that משה said ד' י ל ח ם ל כ ם, ו א ת ם ת ח ר ישׁוּן, Hashem would fight for them, and they didn’t have to do anything.
Here too, Hashem saved בני ישראל from their enemy without their having to do anything. In fact, they were not even aware of the danger they were in! Because of Hashem’s great kindness in doing these miracles for בני ישראל without their having to do anything on their own, בני ישראל sand שירה.
Further discussion
Why did Hashem want to ensure that בני ישראל would know about the miracle at נחל ארנון? (See אות ט in the שיחה)
