Which late 1950s U.S. TV Western series referred to its star as a "knight without armor in a savage land"?

The American Western TV series "Have Gun – Will Travel", which was produced and originally broadcast by the CBS network from 1957 through 1963, referred to its star Paladin (Richard Boone) as a "knight without armor in a savage land". The line was part of the lyrics in the show's popular theme song "The Ballad of Paladin", composed by Johnny Western, Sam Rolfe, and Boone and performed by Western.

In the series, when Paladin (Boone) was not doing his job, he has the persona of being a mild-mannered dandy perched in a luxurious San Francisco hotel, where he sharpens his skills in fencing, chess, and skirt-chasing. He would often now and then exchange repartee (clever conversation) with the mildly flirtatious Hey Girl (Lisa Lu). Then, usually in mid-flirt, some trouble in the town comes to his attention.

He would go out, dressed in black, to wander the plains dealing rough justice with two fists and two shooting-irons. One gun is on his hip and the other is a tiny thing tucked behind his belt buckle. After the problem has been obliterated, Paladin drops a quote by La Fontaine (a French poet) or Pindar (an Ancient Greek lyric poet) and heads for home.

This was a television series that was rated No. 3 or No. 4 in the Nielsen ratings every year of its first four seasons.