There is a lot of debate about how these pieces work. Were they merely status symbols, or could they have served a practical purpose? Swords have been used for both purposes throughout history, and even if they appear unwieldy to our modern standards, they may have worked well enough in the hands of an antagonist in 3000 BCE to ruin your day.
It's like when Jacob listened to his mother and -- dressed in Esau's Sunday Best, essentially the very first Purim costume (Rivka, what a mom) -- got in first to nab Esau's blessing, which then meant that Esau received the blessing about living by his sword. He was blessed with not just the regular dew of heaven (what Jacob 'stole'), but the dew of heaven from above.
Lacking vision and skipping over the fine print, he became incensed, convinced that he got the shaft and that Jacob was "obviously" a real piece of work.
As anyone can see, it doesn't take much for things to go horribly wrong when people jump to conclusions. Judging by his actions, Esau assumed that his sword was an instrument of hate and death. What kind of blessing is that. Yet instead of stopping to think for a moment, he went flying off the handle, enraged. Self-fulfilling prophecy, yikes.
Genesis 27
38 And Esau said unto his father, Hast thou but one blessing, my father? bless me, even me also, O my father. And Esau lifted up his voice, and wept.
39 And Isaac his father answered and said unto him, Behold, thy dwelling shall be the fatness of the earth, and of the dew of heaven from above;
40 And by thy sword shalt thou live, and shalt serve thy brother; and it shall come to pass when thou shalt have the dominion, that thou shalt break his yoke from off thy neck.
41 And Esau hated Jacob because of the blessing wherewith his father blessed him: and Esau said in his heart, The days of mourning for my father are at hand; then will I slay my brother Jacob.
Nobody can take a yoke!
Eh, it'll all work out in end because these boys are twins, the sons of Isaac meaning "he will laugh". And as everyone knows, in *Isaac* is Abraham's seed called. Accept no substitutes.
When Jacob was dubbed "Israel", it was because he wrestled with God and man, and *prevailed*, the verb for "can".
Esau is the "Do" part of the Can-Do team because that's the meaning of his name. It's a key detail. "Time and Date" keeps telling everyone over and over, like on this page:
An Eclipse Never Comes Alone!
Anyone remember a particular spat in the sequel (what a plotline!)? It was when the Heat Miser snapped at the Snow Miser,
"Mother always did like *you* best." 😡
Gotta laugh.
Isaiah 2:4 And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more.