Isaiah Tishby

Scholem ... set about compiling a complete dictionary of the language of the Zohar that would contain every word and idiom and would explain their usage in the different sections of the book. This comprehensive study proved without doubt that, in the first place, the main body of the Zohar was a unified whole, ans that, second, its composition was of late date, for it demonstrated that all the sections had a single linguistic shape and that this shape was full of late expressions and forms that originated in the language of medieval scholars.

p. 55