36. Symbolic Imagery
Yesodei HaTorah 7:3
When a prophet receives a message in a vision, he receives it in metaphoric images. He instantly receives the interpretation of the images so that he understands the prophecy. For example, our Forefather Jacob saw a ladder with angels ascending and descending; this was a symbol for the way various empires would subjugate his descendants. Similarly, the angels that Ezekiel saw, the boiling pot and the almond rod seen by Jeremiah, the scale seen by Zechariah, etc., were all symbolic images. Some prophets would relate both the imagery seen in their visions and the explanation; other prophets would only relate the explanation. Sometimes, a prophet would relate the imagery without the explanation; Ezekiel and Zechariah sometimes did this.
Yesodei HaTorah 7:4
Prophets do not receive messages on demand. Rather, they must focus their attention and sequester themselves. They must be in a cheerful mood, because prophecy cannot rest on a person when he is feeling gloomy. Because of this, the prophets' disciples would carry instruments to help put them in a good mood be so that they could receive prophecies. When I Samuel 10:5 says “They were prophesying,” it means that they were aspiring to achieve prophecy.