God brought them out of Egypt; he hath as it were the strength of an unicorn.
I don't have a hard copy to check. Is that simply a copied typo?
No, it's not a typo. Words starting with u started with a diphthong until the 18th century. This was part of the Great Vowel Shift. The vowel started changing from /yː/ (its original vowel in French1) in Middle English, migrated through several diphthongs, and ended up at /juː/ sometime around the 18th century.
1 At least the upper classes, who were descended from French-speaking Normans, used the original French vowel /y/ for French words spelled with 'u' in Early Middle English. I don't know whether there's any evidence for how the lower classes pronounced this.