The sohemaker's son always goes barefoot

The shoemaker's son always goes barefoot: Proverbial saying, mid 16th century, meaning that the family of a skilled or knowledgeable person are often the last to benefit from their expertise.[oxfordreference.]

The sohemaker's son always goes barefoot: "O filho do sapateiro anda sempre descalço", equivalente a expressão "casa de ferreiro, espeto de pau".