Mambo Ya Walawi 18:17

“ ‘Usikutane kimwili na mwanamke kisha na binti yake. Usikutane kimwili na binti wa mwanawe au binti wa binti yake; hao ni ndugu zake wa karibu. Huo ni uovu.

Thou shalt not uncover the nakedness of a woman and her daughter, neither shalt thou take her son’s daughter, or her daughter’s daughter, to uncover her nakedness; for they are her near kinswomen: it is wickedness.