Cross reference
Leviticus 21:2
2 But only for his near relations, for his mother or his father, his son or his daughter, and his brother;
Leviticus 18:6
6 You may not have sex connection with anyone who is a near relation: I am the Lord.
1 Thessalonians 4:13
13 But it is our desire, brothers, that you may be certain about those who are sleeping; so that you may have no need for sorrow, as others have who are without hope.