In Revelation Lesson 4B it discusses the statue in Nebuchadnezzar's dream from Daniel 2. Pastor Armstrong said that Medo-Persian kingdom was represented by the folding arms of the statue. Where did the folding arms come from? I can't seem to find this description.
You are correct that the text does not specify the position of the arms in the statue. Pastor Armstrong was referring to an example image of the statute that accompanied the study. In that image, the arms of the man were portrayed as folded. The artist assumed the arms were folded because Daniel reported that the statue’s silver content ceased at the “belly” (v.32), yet if the arms were hanging down by the statue’s side, then silver would extend below the belly of bronze.
Therefore, the artist assumed that the arms were folded so that the division between silver and bronze was maintained. Nevertheless, the image is only an “artist’s conception” of how the statue may have appeared, and therefore it is not authoritative. Another diagram in the lesson shows a silhouette of a man with arms hanging by his side. However, the point to take note of with the statue is not body position, but the change in materials – and thus kingdoms – as you move down the statue.