Allah wrote:We bestowed Grace aforetime on David from ourselves: "O ye Mountains! Sing ye back the Praises of Allah with him! and ye birds (also)! And We made the iron soft for him; (Commanding), "Make thou coast of mail, balancing well the rings of chain armour, and work ye righteousness; for be sure I see (clearly) all that ye do."
So here Allah talks about king David and not some other David, and just so there is no doubt about that, Solomon is mentioned straight afterwards. He instructs David to make CHAIN MAIL. Odd thing to be asked by the Lord of all the universes, make chain mail, but here we go.
Now, King David died around 970BC, give and take a few years, we don't know the exact dates. So he lived around 1000 BC.
And chain mail? This is a Celtic (Scottish/Irish/Northern French) invention from no earlier that 500 BC, and it did not reach the Middle East until some 800 years later, even though it was used in Persia before then who may have come up with the idea independently, or they copied it from the Romans, after they copied it from the Celts.
So David would not have any idea what chain mail is, and he certainly never used any.
To Mohammed, chain mail was cutting edge technology, and he wore chain mail when entering Mecca. Now, SAM, have you noticed how older "prophets" somehow always end up imitating Mohammed's acts, even though long dead, and nobody before Mohammed knew about that?
Do you want to explain this SAM? HMMM?