Small note found in the monastery (Kingdom Come: Deliverance)

Can you please tell me about what specific place does the note say and what should I find there? The text of the note, "Remember: go down from the Gates of Faith between the shadow of the cathedral and the wooden palisade, walk with repentance through a dry river bed under a large bridge. Like Moses, fearlessly walk along the bottom, go out on land among the reeds, find faith and search in the burning bush. "
PS It seems to me that I still found the place, but there is no chest, no grave, no pile that can be examined there ... Either I am blind or I already found the treasure earlier by simply exploring the territory before the quest in the monastery ...