The psalmist, speaking for his nation, called the other nations to join in praise of God by shouting, singing, and speaking. In Psalm 66:1-12 he wrote in the first person plural, but in Psalm 66:13-20 he used the first person singular. God"s great acts made His enemies cringe before Him. "Feigned obedience" ( Psalm 66:3, NASB) is hypocritical obedience. The psalmist meant that God"s enemies would pretend to obey Him because they feared His wrath, even if they did not really obey Him. [source][source][source]