Israel's troubles and God's righteousness. There is reference to those who oppose spiritual things, and therefore attack the people of God. Scripture teaches that there is no middle ground; we are either for Him, or against Him.
This set of three; considering past afflictions (Ps 129), through the experience of forgiveness (Ps 130), into real trust and hope in God (Ps 131).
v1-2: Afflictions "from my youth," repeated over many years. This is the testimony of Israel as a people, as well as of the godly individual. But they had not prevailed, although the suffering was real.
v3-4: The Lord Jesus allowed men to mistreat Him; His suffering was equally real. The Lord God is righteous, and sends deliverance; ultimately there will be a demonstration of God's righteous judgment.
v5-7: The test is their attitude to Zion; today, the touchstone is their belief, or otherwise, in Christ. Such that hate Zion will suffer loss (see Esth 6.13); the psalmist prays what God has declared.
v8: The unbelieving miss out on God's blessing. Outside of His promises, there is no reason why He should bless. True believers bless each other.