What explains the psalmist’s switching between the singular and plural when speaking of the enemy in 17:9–14?
David refers to the wicked
in Psalm 17:9–11, but now switches to speaking of his enemies in the singular, likening the enemy to a lion. Also in Psalm 17:13 he uses the singular him,
calling the Lord to confront the enemy. And then in Psalm 17:14 he returns to plural references. David is not speaking from confusion in these verses. Rather, it could well be that when speaking in the singular, he is either regarding his enemies collectively, or he is singling out a representative of the group. Perhaps David is referring to a situation where Saul is the wicked man (singular) and his followers are those noted in the plural.
12 He is like a lion eager to tear, as a young lion lurking in ambush.