Psalm 17:10 New English Translation

¹⁰They are calloused;^[a]
they speak arrogantly.^[b]

Psalm 17:10 tn Heb “their fat they close.” The Hebrew term חֵלֶב (khelev, “fat”) appears to stand by metonymy for their calloused hearts. They attack the psalmist without feeling any pity or remorse. Some propose emending the text to חֵלֶב לִבָּמוֹ (khelev libbamo, “fat of their heart[s]; cf. Ps 119:70, “their heart is insensitive like fat”). This assumes haplography of the לב (lamed-bet) consonantal sequence.
Psalm 17:10 tn Heb “[with] their mouth they speak with arrogance.”

New English Translation (NET)