Mambo Ya Walawi 20:11

“ ‘Kama mtu atakutana kimwili na mke wa baba yake, hakumheshimu baba yake. Mwanaume huyo na mwanamke huyo wote wauawe; damu yao itakuwa juu ya vichwa vyao wenyewe.

And the man that lieth with his father’s wife hath uncovered his father’s nakedness: both of them shall surely be put to death; their blood shall be upon them.