The Jewish dialect of ʿĀna exhibits three synchronic vowel qualities for the prefix vowel in the prefix-conjugation of the first stem: a, ǝ, and u. While the latter vowel is an allophone of ǝ, the former two are independent phonemes. The existence of two phonemic prefix vowels, especially the vowel a, is intriguing in regional context since the reconstructed prefix vowel in qǝltu dialects is assumed to be *i. Therefore, this paper aims to outline the historical developments that led to this synchronic reality. It will argue that the prefix vowel a was borrowed from surrounding Bedouin dialects. As for the vowel ǝ, two hypotheses will be suggested to explain its existence: it either developed from the prefix vowel a in analogy to other cases of vowel raising, or it is simply a reflection of the older qǝltu prefix vowel. Regardless of which hypothesis we choose to follow, the assumed historical development has clearly not been finalised, resulting in synchronic free variation.