Parallel
Isaiah 58:4
Brenton's English Septuagint · Berean Standard Bible
If ye fast for quarrels and strifes, and smite the lowly with [your] fists, wherefore do ye fast to me as [ye do] this day, so that your voice may be heard in crying?
You fast with contention and strife to strike viciously with your fist. You cannot fast as you do today and have your voice be heard on high.