The King James Version of the Bible sometimes uses the word "an" before a word starting with the letter "h".
One such example is Genesis 2:18, which mentions "an help meet". In Mr. Deity and the Help Meet, Mr. Deity is upset that this mistake was not fixed, saying, "That's an horrendous idea." Lucy says "an healthy, nutritious meal" later in the episode.
Brian Dalton sometimes uses "an" before H-words as a joke. Also, in the description box on YouTube for Mr. Deity and Da Man, he says, "Mr. Deity and Larry prepare Adam for an wife."