Psalm 103:9 New English Translation

⁹He does not always accuse,
and does not stay angry.^[a]

Psalm 103:9 tn The Hebrew verb נָטַר (natar) is usually taken to mean “to keep; to guard,” with “anger” being understood by ellipsis. The idiom “to guard anger” is then understood to mean “to remain angry” (see Lev 19:18; Jer 3:5, 12; Nah 1:2). However, it is possible that this is a homonymic root meaning “to be angry” (see HALOT 695 s.v. נטר).

New English Translation (NET)