This psalm belongs to a group of psalms called the "Songs of Degrees" or "Songs of Ascents." See Psalms 120 - 134. Warren Wiersbe calls them "Pilgrim Psalms." They were used as a selection of hymns to be sung while ascending into Jerusalem to observe various festivals. They were reminders of their national and personal blessings from God. In acknowledging the blessings of the Lord, the subject of Israel's sufferings and persecutions is a topic of consideration. Psalm 129 acknowledges that God's people have always had enemies, but God has preserved them through all persecution.
The Fact of Persecution - Psalm 129:1-2
It seems to be a part of the prescription of God for His people to suffer at the hands of the ungodly. It is not a strange new thing (I Peter 4:12; II Timothy 3:12). We must keep our focus on the Lord, not on our enemies (John 16:33).
The Focus of Persecution - Psalm 129:3-4
While focusing on the Lord, we must look for His purposes for bringing suffering and persecution into our lives. Much of the time, Israel suffered and received persecution because they were being corrected for their disobedience and waywardness (Psalm 106:1-48). Sometimes we can see greater prophetic purposes that were being fulfilled. The things that befell Israel made the way for the Scriptures to be written and established, so that, from the nation Israel, we could have our Savior, the Lord Jesus Christ (Romans 9:4-5; 11:25). We need to see persecution for Christ's sake as a bestowment from God for character building, as a way to glorify the Lord and to advance the kingdom of Christ (II Corinthians 1:3-7; 12:7-10; I Peter 4:12-19; Philippians 1:27-30).
The Future of Persecution - Psalm 129:5-8
The wicked are described as the short-lived grass that grows on the flat roofs of their houses. It will not be harvested. Therefore, blessings will not be pronounced, as they are in the fields during harvest.
It is important to know that suffering and persecution are a temporary feature in our lives. God's grace and glory continue through and eternally after our earthly sorrows (II Corinthians 4:6-18). The people of Israel needed to observe God's preservation through their troubles and His triumph for them after their troubles. We can take comfort in knowing that evil shall not prevail, and that God will bring everything to a good and righteous conclusion (Matthew 16:18: II Thessalonians 1:3-12; II Peter 3:10-15; Revelation 19:11 - 21:8).
This psalm makes us consider the purpose of imprecatory Psalms (i.e. Psalms that invoke God's wrath and judgement on the wicked). This type of psalm seems to contradict the clear New Testament teaching to love our enemies and to show mercy and forgiveness (Matthew 5:43-48; Romans 12:12,14,17-21). We offer a few simple principles to help with this paradox.
Old Testament Israel
Under the old covenant and dispensation of the law, Israel (God's people) were trying to survive and thrive in the world as a people that were holy / separated unto the Lord. The nation had to fight to survive, but they had to do it with God's help and guidance. Their wars were very physical. See Psalm 83.
New Testament Kingdom of Christ
The nature of Christ's Kingdom today is very spiritual. It is not limited to any geographical location, or particular ethnic group of people (Romans 3:9,19-24,28-30; Galatians 3:27; Revelation 5:9). Being of a spiritual nature, this kingdom has a warfare that is not physical / carnal and cannot be fought with physical / carnal weapons (John 3:3; 18:36; II Corinthians 10:3-5; II Thessalonians 3:1-2; Ephesians 3:10-20).
Christ in the Psalms
Christ is revealed in many ways in the Psalms (Luke 24:44; Colossians 3:16). King David is a type of Christ. When we see David seeking victory over His personal enemies and Israel's enemies (Psalm 3:1-8; 5:1-12; 6:1-10; 7:1-17; 18:25-42), we can see Christ and His victory over the world, conquering His enemies (which includes sin, Satan, and death - I Corinthians 15:24-28). See in the Psalms where Jesus Christ is prophetically revealed as the son of David / The King / God's Anointed Messiah / God's Son: Psalm 2:1-12; 45:1-17; 72:1-17; 89:3-37; 110:1-7; 132:1-18.
We can use the imprecatory Psalms as words of warfare against our own sinful tendencies and temptations in the world (Romans 8:12-13; Colossians 3:1-10; II Timothy 2:3-4) and also against Satan and his demons - against a dark spiritual kingdom at work in this world. In gospel warfare, humans are not to be fought in any physical sense. Rather, they are to be rescued. See Galatians 1:3-4; Colossians 1:13; Ephesians 6:11-12; James 4:1-10; I Peter 5:6-10; I John 4:1-6; 5:1-5,19-20; Romans 16:20; I Timothy 2:1-6; II Timothy 2:8-10,24-26.