'Expression' in the Bible

Jesus replied to him, “It is written and forever remains written, ‘Man shall not live by bread alone.’”

lying in wait to catch some unguarded expression from His lips.

So, after impatiently watching their opportunity, they sent spies who were to act the part of good and honest men, that they might fasten on some expression of His, so as to hand Him over to the ruling power and the Governor's authority.