Leviticus 21:2-4

New American Standard Bible

^2 (A)except for his relatives who are nearest to him, his mother, his father, his son, his daughter, and his brother, ³ also for his virgin sister who is near to him ^[a]because she has not had a husband; for her, he may defile himself. ⁴ He shall not defile himself as a ^[b]relative by marriage among his people, so as to profane himself.