Ruth 4:6

lest I mar mine own inheritance When the Go'el learns that if he redeems the estate he is expected to marry the widow, he takes back his promise (Ruth 4:4). He declares that he cannot afford to be so generous. If he were to have a son by Ruth, the child would take the name and estate of the dead, and the Go'el would have only a temporary usufruct in the property, and in the end lose it altogether (Robertson Smith l.c.).

take thou my right of redemption on thee Since the Go'el declines, the right to redeem falls on Boaz as the next nearest kinsman.