I thought the same thing on reading that line. My reaction was that it might could have been echoing a Hebrew poetic trope of repetition.
Good catch Faldage! עַרְעֵר תִּתְעַרְעָר is literally broken with brokenness or undermined with undermining. See here. My wife uses this format often. “That guy is dead, dead” she might say after a bad guy was beaten down in a cop show. The AV translates it as “Utterly broken” suggesting that the first ‘arar is an adverbial intensifier of some sort.
edit: This construction is fairly common in biblical Hebrew. In Isaiah 29:9 the AV does repeat the repetition, “Stay yourselves, and wonder; cry ye out, and cry: they are drunken, but not with wine; they stagger, but not with strong drink.”
Interestingly the repetition of “evermore and evermore” of Isaiah 34:10 is preserved in a well-known 13th c. Plainsong chant “Of the Father’s Love Begotten” (actually a 4th c. poem). It is repeated at the end of all four verses.