that they
Genesis 38:11
And Judah saith to Tamar his daughter-in-law, 'Abide a widow at thy father's house, till Shelah my son groweth up;' for he said, 'Lest he die -- even he -- like his brethren;' and Tamar goeth and dwelleth at her father's house.
Deuteronomy 25:5
'When brethren dwell together, and one of them hath died, and hath no son, the wife of the dead is not without to a strange man; her husband's brother doth go in unto her, and hath taken her to him for a wife, and doth perform the duty of her husband's brother;