What does Genesis 38:11 mean?

Judah told Tamar, 'Go live as a widow at your father’s house until my son Shelah grows up.' He was afraid Shelah would die too, like his brothers. So Tamar went to live with her father. Genesis 38:11 - Modern Text Bible

(Judah promises Tamar another marriage but is really just trying to protect his last son, leaving Tamar in limbo.)