A detective superintendent has been placed on ‘restricted duties’ while the Independent Office for Police Conduct investigates a complaint that he used the phrase whiter than white at a briefing. An ‘insider’ told the Evening Standard: ‘It may have been a poor use of language but this is not what the misconduct process is for.’

What nonsense. It is isn’t ‘a poor use of language’ at all. We may take it that the phrase was used figuratively. Literally, whiter than white has been used of necks, teeth and faces for three or four hundred years. In the figurative sense, I cannot find anything definite before 1962, about the time when lily-white in the same sense may be found.

Tottenham Hotspur are nicknamed the Lilywhites from their shirts. This is a sobriquet less controversial than one adopted by fans: Yids or Yiddos. It is a tribute to the open-mindedness of the Jewish Chronicle that it carried an extract from a history of Spurs which, while noting that some people feel that Yids is not a word Spurs fans are entitled to embrace, concluded that ‘using the word as a term of endearment and comradeship nullified the negativity’.

Anyway, expressing moral purity by the metaphor of whiteness is deeply embedded in Western culture and in Hebrew culture before it. ‘Wash me, and I shall be whiter than snow,’ says the penitential Psalm. At his transfiguration, the clothes of Jesus became ‘exceeding white as snow; so as no fuller on earth can white them’.

The Oxford English Dictionary prosaically notes that whiter than white was ‘popularised in the 20th century as an advertising slogan for Persil washing powder’. I remember better the slogan ‘Persil washes whiter’; in one advertisement from 1968 it was sung to the tune of Buddy Holly’s ‘Every Day’: ‘Persil aut-o-matic washes whiter.’

On the constabulary front, John Mortimer, in Rumpole and the Penge Bungalow Murders (2004) included a detective inspector nicknamed Persil not just because his surname was White but also because he was ‘always telling people he’s whiter than white’, in other words not corrupt. Racial considerations didn’t come into it.