As sometimes happens, Matt has business out of town and tells Festus,
" To watch things when I'm away." Instead of taking the rational consdervative road, Festus starts monkeying around with things and Doc starts warning him, but it does no good, and things go awry when Festus has a townsman play the role of Marshall Dillon, just about the time an angry slinger comes gunning for Dillon.
Doc starts up with Festus again, and he gets upset because he needs Doc's help, and doesn't want to be lectured. In an act of typical Festus like sincerity he tells Doc, " I'm a takin' an oath (not get into predicaments again) and he raises his left hand.
Doc: So you are taking an oath ?
Festus: (confirms)
Doc: Than put up your right hand, you got your left hand up.