From Genesis to Revelation we find them, the most intriguing of which are to be found in Deuteronomy and the Book of Job.
This is a very interesting study to undertake and quite mysterious as well.
Below, I have included the definition of the term for this phenomenon and some useful links to get you started in a study of
rpus linguistics, a hapax legomenon (/ˈhæpəks lᵻˈɡɒmᵻnɒn/ also /ˈhæpæks/ or /ˈheɪpæks/; pl.
hapax legomena; sometimes abbreviated to hapax, pl. hapaxes) is a word that occurs only once within a context,
either in the written record of an entire language, in the works of an author, or in a single text
Words That Occur in the Bible Only Once—How Hard Are They to Translate?
By Frederick E. Greenspahn
For over a thousand years, students of the Hebrew Bible have been intrigued by the fact that some words in the text occur only once. Medieval Jewish manuscripts mark these unique forms with the Hebrew letter lamed, an abbreviation for the Aramaic word layt, which means “there is no other.” The Masoretes, medieval scholars who sought to preserve and fix the text in its authentic form, made lists of such words, presumably for the benefit of scribes who might otherwise have thought the words wrong just because they were unique. Medieval Jewish interpreters of the Bible described words for which they could find no parallel as “one of a kind,” having no “friend,” “brother,” or even “father and mother.”