And the messengers returned to Jacob, saying: “We came to thy brother Esau, and moreover he cometh to meet thee, and four hundred men with him.” (Gen. 32:7)
Why does the Torah take pains to tells us the exact number of men accompanying Esau? Servants of Esau are of no particular significance. It is apparent that, by specifying the number of men in Esau’s entourage, the Torah is trying to tell us something about Esau.
It seems to me that Jacob understood the significance of the number 400. This number is a sum of the powers of 7 from 0 to 3: 70+71+72+73=400.
This four powers of 7 hint at the lunar month that has, approximately, 28 days (4×7). The significance of this will become apparent later. 400 is a repdigit in base 7 (1111). Esau and his 400 men together were 401 strong. 401 is a prime number that is the sum of seven consecutive prime numbers (43+47+53+59+61+67+71). It’s all about the number 7! Jacob may have alluded to this by bowing down to his brother seven times as he approached Esau.
More significantly, though, the number 400 is an important number in astronomy of the Solar system. If you ever watch sunset long enough, you might have noticed that as the Sun sets beyond the horizon and the Moon rises in the night sky, they appear to be roughly the same size. How could that be? Isn’t the Sun much bigger than the Moon? You have the number 400 to blame!
Indeed, the Sun is roughly 400 times larger than the Moon. The Sun is also about 400 times further away from the Earth than the Moon. Hence the two appear to be about the same size. This was already well understood in Antiquity by Aristarchus (310 – 230 B.C.), although he erred as to actual size and distance.
This coincidence makes total solar eclipse possible.
What significance, however, it has to the Biblical story of Jacob and Esau?
Just as the Moon and the Sun appear to be of the same size, Jacob and Esau appear to be twin brothers. In reality, however, just as the Moon and the Sun are very different in size and in nature (former being a planet and the latter being a star), so too, there is little in common between Jacob and Esau. As I wrote in my essay,, God’s choice of Jacob over Esau is a metaphor for spontaneous symmetry breaking:
I loved you, said the Lord, and you said, “How have You loved us?” Was not Esau a brother to Jacob? says the Lord. And I loved Jacob. And I hated Esau (Malachi I, 2-3)
Jewish people – the descendants of Jacob – are compared to the Moon, whereas Gentiles – the descendants of Esau – are compared to the Sun. Indeed, “…the gentiles reckon their calendar by the sun and Israel by the moon.” (Babylonian Talmud, tr. Sukkah 2:9) While, historically, Jewish people’s fortune has been waxing and waning, the moon is ultimately the symbol of rebirth and renewal. Is this what the Torah hints at by counting Esau’s entourage?