The Secrets of the Saffron Mountain. Mark Cohn Series, #2

Action, romance, travel and history abound in the second book of the Mark Cohn series. Mark and his husband, archeologist Eric Jansen, are traveling across Israel's Negev Desert to Mount Karkom-"the Saffron Mountain, " a rock formation entrenched in Biblical legend, where the phenomenon of the Burning Bush is still visible on the winter equinox. Mark and Eric are convinced the cave dwelling at the summit contains proof the rock is indeed Mount Sinai, and the events of the Book of Exodus are true.
Embedded in their expedition is an orthodox rabbi appointed by the government to supervise their efforts and prevent damage to any sacred sites or objects. Once in the cave, however, Eric's archeological expertise and Mark's metaphysical instincts reveal clues leading to the discovery of a second cave containing hidden treasure-a vast array of wealth taken by the Israelites during their flight from Egypt, and an emerging story that doesn't quite align with the Bible...
It's a race against time as Mark and Eric work to solve an ancient mystery before the government and religious authorities shut down their efforts and the precious knowledge is lost forever.