Some people swear by it first thing in the morning.
I won't carry one again, but some people swear by them.
I'm still not sure how well this works, but the players swear by it, and they're the ones on the ice.
Still, some of the patients and their family members who testified at the meeting swore by the drug.
"I swear it by earth and water," said the boy in green.
I swear it by the old gods and the new.
She has him swear by his prognosis, which he does.
Never to speak of this that you have heard: Swear by my sword.
"My father used to swear by them, too," she told him.
I swear by all the saints you are talking to the wrong man,' he whispered.