On the southeast side of the pavilion stood a monastic hall (vihara). It is a brick-and-mortar building with a high base and a surrounding outer wall.
The temple is mentioned in the Royal Chronicles of Ayutthaya. After the war with the Burmese in 1760 CE, the ex-King Uthumphon (reign 1758 CE), also known as Khun Luang Ha Wat, sought safety here from the malpractices of his elder brother, King Suriyamarin (reign 1758-1767 CE), who could not cope well with Ayutthaya’s successful defence and the popularity of his younger brother. Prince Uthumphon left the Front Palace by royal barge and went to the Kham Yat Royal Residence before ordaining at the nearby Wat Pho Thong. After his ordination, he went to stay at Wat Pradu, as before the war.
“One day later on, during the middle of the night, the King issued a holy royal proclamation to have the Holy Younger Brother of the King summoned in for an audience in a place in the Interior [of the Palace Enclosure]. When His Majesty went in He gazed with His holy eyes and saw His Holy Lord and Older Sibling unsheathe a holy sword weapon and lay it across His holy lap. He accordingly understood in His holy heart that the King was displeased, would do Him harm, and would not let Him remain among the laity. His Majesty thereupon came back out to His place to the Front [of the Palace Enclosure]. When the waxing half of the eighth month arrived, His Majesty thereupon boarded a holy throne barge and went out to the Monastery of the Fig of the Pure Gold Spray. After entering the holy monkhood, His Majesty came back in to live at the Monastery of the Pradu Tree just as before.” [1]
Prince Damrong cited the events in the paragraph above in his book “Our Wars with the Burmese”.
“Those government servants who did not agree with Somdet Phrachao Uthumphon sought for power as formerly. They incited Somdet Phrachao Ekathat to hate, doubt, and be jealous of Somdet Phrachao Uthumphon. The royal history states that, on one occasion, Somdet Phrachao Ekathat invited Somdet Phrachao Uthumphon to see him at night. When the latter arrived, he saw Somdet Phrachao Ekathat draw his sword from the scabbard and place it on his lap. Somdet Phrachao Uthumphon believed that, because his brother was at enmity with him, if he persisted in staying at the capital, there might be fighting between them. So he went away from his palace and stayed at a temporary palace in the village of Kham Yat in the district of Muang Wiset Chaichan. When he had made preparations and was ready to go, he entered the priesthood at the Pho Thong monastery which was near his temporary palace, and came and stayed at the Pradu Rongtham monastery as formerly. At that time, most of the government servants who belonged to the party of Somdet Phrachao Uthumphon entered the priesthood along with His Majesty.” [2]