And the kinsman said, I cannot redeem it for myself, lest I mar mine own inheritance: redeem thou my right to thyself; for I cannot redeem it.

Wesley's Notes

4:6 Mar - Either because having no children of his own, he might have one, and but one son by Ruth, who, though he should carry away his inheritance, yet would not bear his name, but the name of Ruth's husband; and so by preserving another man's name, he should lose his own. Or, because as his inheritance would be but very little increased by this marriage, so it might be much diminished by being divided amongst his many children, which he possibly had already, and might probably have more by Ruth. My right - Which I freely resign to thee.

Jamieson-Fausset-Brown Bible Commentary

Ru 4:6-8. He Refuses the Redemption.

6. The kinsman said, I cannot redeem it ., lest I mar mine own inheritance-This consequence would follow, either, first, from his having a son by Ruth, who, though heir to the property, would not bear his name; his name would be extinguished in that of her former husband; or, secondly, from its having to be subdivided among his other children, which he had probably by a previous marriage. This right, therefore, was renounced and assigned in favor of Boaz, in the way of whose marriage with Ruth the only existing obstacle was now removed.

Matthew Henry's Concise Commentary

4:1-8 This matter depended on the laws given by Moses about inheritances, and doubtless the whole was settled in the regular and legal manner. This kinsman, when he heard the conditions of the bargain, refused it. In like manner many are shy of the great redemption; they are not willing to espouse religion; they have heard well of it, and have nothing to say against it; they will give it their good word, but they are willing to part with it, and cannot be bound to it, for fear of marring their own inheritance in this world. The right was resigned to Boaz. Fair and open dealing in all matters of contract and trade, is what all must make conscience of, who would approve themselves true Israelites, without guile. Honesty will be found the best policy.