4:6 The comment of many people David quoted reflects the spirit of discontent with present conditions that had led them to oppose the king. Their desire for good was legitimate. David asked God to show them good by blessing them. Causing God's face to shine on His people is a figure of speech for bestowing His favor on them (cf. 31:16; 44:3; 67:1; 80:3, 7, 19; 119:135).
4:7 Knowing he was God's chosen servant and that those who sought to overthrow him were acting contrary to the will of God brought great joy to David's heart. He said he felt more joy than he experienced during Israel's harvest festivals that were some to the happiest occasions in the year.
4:8 He could rest and sleep peacefully with this knowledge (cf. 3:5). Even though many sinners opposed him he was right with his righteous God. He knew God would protect him.
The elect of God can experience true joy and peace even thought the ungodly may oppose them because He will protect and provide for them (cf. Gal. 5:22; Rom. 14:17).
