Bewitched - Season 5 - Eps 18: Samantha the Bard
Samantha is speaking in rhymes, which turns out to be a bad thing when Darrin is entertaining a client who has been using jingles for years and is tired of them. Larry gets tired of Samantha rhyming and wants her to quit it. Dr. Bombay comes by and gets Samantha to stop rhyming. She then explains to the client that she spoke in rhymes to prove how annoying they can be.
About Bewitched

Title: Bewitched
First Air Date: 1964-09-17
Last Air Date: 1972-03-25
Status: Ended
Rating: 7.861/10 (from 695 votes)
Language: EN
Seasons: 8
Total Episodes: 254
Network: ABC
Genres: Sci-Fi & Fantasy, Comedy, Family, Drama
Production Companies: Columbia Pictures Television, Screen Gems
Synopsis
Samantha Stephens is a seemingly normal suburban housewife who also happens to be a genuine witch, with all the requisite magical powers. Her husband Darrin insists that Samantha keep her witchcraft under wraps, but situations invariably require her to indulge her powers while keeping her bothersome mother Endora at bay.
Cast

Elizabeth Montgomery
Samantha Stephens

Dick Sargent
Darrin Stephens

Agnes Moorehead
Endora

David White
Larry Tate