The Faithful Shepherd (Hebrew: רעיא מהימנא) is the name that the Zohar refers to Moses when he comes to support and add to Rabbi Shimon in his studies.
There was a separate book, “The Faithful Shepherd” “ספר רעיא מהימנא” with this name, but the first editors of the Zohar inserted different parts from it where it is most related to the subject discussed in the Zohar.
Synonyms:
רעיא מהימנא