“They loved each other with their (entire) soul.” (Shmuel Aleph 20:17)
This sentence reflects the love between King David and Yonatan, who was the son of King Shaul. In the touching narrative from the Prophets Yonatan sees the special qualities of (King) David, the youth who would play the harp for his father, and remains loyal to protect him. This biblical phrase is therefore chosen to express the love between parents and children which especially reveals itself at the high moment of the circumcision ceremony.