JFB : Psalms 3

      @Ps 3:1-8. For the historical occasion mentioned, compare @2Sa 15:1-17:29. David, in the midst of great distress, with filial confidence, implores God's aid, and, anticipating relief, offers praise.

      1. Lord . . . increased--The extent of the rebellion (@2Sa 15:13) surprises and grieves him.

      2. say of my soul--that is, "of me" (compare @Ps 25:3). This use of "soul" is common; perhaps it arose from regarding the soul as man's chief part.
      no help . . . in God--rejected by Him. This is the bitterest reproach for a pious man, and denotes a spirit of malignant triumph.
      Selah--This word is of very obscure meaning. It probably denotes rest or pause, both as to the music and singing, intimating something emphatic in the sentiment (compare @Ps 9:16).

      3. But--literally, "and" (@Ps 2:6). He repels the reproach by avowing his continued trust.
      shield--a favorite and often-used figure for protection.
      my glory--its source.
      lifter up of mine head--one who raises me from despondency.

      4. cried . . . heard--Such has been my experience. The latter verb denotes a gracious hearing or answering.
      out of--or, "from."
      his holy hill--Zion (@Ps 2:6). His visible earthly residence.

      5. the Lord sustained me--literally, "will sustain me," the reason of his composure.

      6. ten thousands of people--or, "myriads," any very great number (compare @2Sa 16:18).

      7. Arise, O Lord--God is figuratively represented as asleep to denote His apparent indifference (@Ps 7:6). The use of "cheekbone" and "teeth" represents his enemies as fierce, like wild beasts ready to devour (@Ps 27:2), and smiting their cheekbone (@1Ki 22:24) denotes violence and insult.
      thou hast broken--God took his part, utterly depriving the enemy of power to injure.

      8. an ascription of praise to a delivering God, whose favor is an efficient benefit.