Blood and Blood

Any ideas what this phrase means?

10 And what cause soever shall come to you of your brethren that dwell in their cities, between blood and blood, between law and commandment, statutes and judgments, ye shall even warn them that they trespass not against the Lord, and so wrath come upon you, and upon your brethren: this do, and ye shall not trespass.

https://www.churchofjesuschrist.org/study/scriptures/ot/2-chr/19?lang=eng&id=p10#p10