Why does Tyndale write "an whore" and not "a whore" in Deut. 23:18?

Tyndale Deut. 23.18:

"Thou shalt nether brynge the hyre of an whore nor the pryce of a dogge in to the housse of the Lorde thy God."

I pronounce the word "whore" with a voiceless consonant /wh/ at the beginning as in "who," similarly to /h/ "horse." Thus, I would say "a whore," following the rule that "a" precedes consonants and "an" precedes vowels.

Is it that Tyndale would've pronounced "whore" something like "oar," without a leading consonant, thus justifying using "an?" Or is he following a different rule than what I just described? i.e.

Wycliffe Deut. 23.18:

"Thou schalt not offre the hire of `an hoore hows, nether the prijs of a dogge"

Is Tyndale just following Wycliffe's lead? If so, why did Wycliffe use "an?"

The Wh- spelling for whore is not etymological; the W was not part of the original pronunciation and was added rather accidentally, as it were.

Etymonline has it that

This is reconstructed to be from Proto-Germanic *hōran-, fem. *hōrā- (source also of Old Frisian hor "fornication," Old Norse hora "adulteress," Danish hore, Swedish hora, Dutch hoer, Old High German huora "prostitute;" in Gothic only in the masc. hors "adulterer, fornicator," also as a verb, horinon "commit adultery"). It is considered to be, probably, etymologically, "one who desires," from PIE root *ka- "to like, desire," which in other languages has produced words for "lover; friend."

Whore itself is perhaps a Germanic euphemism for a word that has not survived. The Old English vowel naturally would have yielded *hoor, which is the pronunciation in some dialects; it might have shifted by influence of Middle English homonym hore "physical filth, slime," also "moral corruption, sin," from Old English horh.

That is, historically, whore begins with only the H sound and not a W sound, leaving it open to debate whether its article should be an or a (an was sometimes used before an initial h, which was often muted in word from Latin and French origins).

Wycliffe lived only some sixty years before Tyndale; while it is apparent that the Wh- spelling was coming into use or being consolidated over that time, it is also clear that the article was not uniformly or universally adapted to the new spelling; Tyndale likely was familiar with Wycliff's translation and may have followed his precedent, but he also could have kept the an article simply because the word began with an H sound.