Andrew Bonar writes to his brother William, encouraging him to explore Jerusalem and its significant sites, such as the Mount of Olives and the Pool of Siloam, while reflecting on the spiritual truths they represent. He emphasizes the importance of connecting with the history and presence of Jesus in these holy places, suggesting that such a journey can be healing for the soul. Bonar also humorously notes the inaccuracies in a map of Jerusalem, while expressing his hope that William will encounter the divine as he wanders through these sacred locations.