Balentine again: He points out that Job receives double back from God in the epilogue. “His possessions are returned to him twofold (42:12; compare 1:3). His family is restored with the birth of ten children, seven sons, and three daughters (42:13-15). Job’s doubly blessed life enables him to see four generations of his progeny. After 140 years of postcatastrophe life (42:16), twice the normal lifespan (compare Ps 90:10), Job dies “old and full of days” (42:17)…”
Of course the law requires twofold restitution to be paid for any manner of loss or trespass against a neighbor’s property (Ex. 22:9).