昔

xi

past, ancient, former, times

昔日  former days, the past; 

今昔 now & then (poetic way to contrast past and present)

It is believed that character symbolizes the past or the former days (日) of the flood ().

借

jie

to lend; to borrow

借钱 borrow money; 借书 borrow books

借光 ask for favor (lit. borrow light); 借口 excuse (lit. borrowed words)

a person (亻) turns toward the past (昔) to recall what is borrowed or lended

钅

jin

metal

钅 looks like a tiny hooked ingot (金’s essence) — it turns characters into metal words

错

cuo

error, blunder, mistake, wrong

交错 crisscrossed; 对错 right and wrong

to create a metal relying on the techniques from the past would be wrong