In "Takahashi uji bumi" where the place of the Kashiwade clan's origin was stated to be, it described that when Emperor Keiko visited the eastern province, Iwamutsukarinomikoto (known as the founder of the Kashiwade clan) in Awa Province, caught clams, cooked, and offered them to the Emperor, then he was offered to be Kashiwadenoomi (a leading figure who managed to supply food to the Emperor) to supply food to the Emperor's posterity.
膳氏の出自を示した『高橋氏文』には、景行天皇が東国に行幸したおりに、安房国にて磐鹿六雁命（いわむつかりのみこと、膳氏の始祖とされる）が蛤（はまぐり）を捕り、天皇に料理をして献上したところ、天皇の子孫代まで御食（みけつ）を供するよう膳臣を授かったという記述がある。