A popular picture of Hanuman shows him tearing open his chest. Inside, “everyone is stunned to see Rama and Sita literally in his heart,” as one retelling puts it.
Its origin is less clear. The scene “does not appear in Valmiki’s Ramayan,” the Indian site Shikshanam notes, and it says that the scene is also missing from the Ramcharitmanas. It notes that the scene appears in the Krittivasi Ramayan, a Bengali retelling of the 15th century. That origin rests on this one source.