 A special category of Ancient Egyptian funerary texts clarify the purposes of the burial customs.The early mastaba type of tomb had a sealed underground burial chamber but an offering-chamber on the ground level for visits by the living, a pattern repeated in later types of tomb.A Ka statue effigy of the deceased might be walled up in a "serdab" connected to the offering chamber by vents that allowed the smell of incense to reach the effigy.