One of Democratic presidential candidate Joe Biden’s most well-known character traits is his colorful way of speaking; sometimes he’s telling stories about being a teenager at a swimming pool, sometimes he’s reminiscing about how his dad used to drive cars, sometimes he’s putting his foot in his mouth, and sometimes he’s resurrecting decades-old words like “malarkey” and plastering them across buses. During Tuesday night’s debates, he added a new phrase to his ever-shifting lexicon – “Inshallah.” Mr. Biden deployed the phrase in a testy exchange with Donald Trump regarding his still-unreleased tax returns. “Millions of dollars, and you’ll get to...