Psalms 136:20 in the King James Version reads, "Who remembered us in our low estate: for his mercy endureth for ever." This verse is part of a longer passage that recounts the history of Israel and celebrates God's faithfulness and mercy. The Psalm as a whole is a litany of thanksgiving, with each verse ending with the refrain, "for his mercy endureth for ever."

The verse 20, in particular, speaks to the theme of God's faithfulness to His people, even in their times of greatest need. The phrase "low estate" can be understood as a reference to the condition of Israel when they were slaves in Egypt, or perhaps to any other period of hardship and suffering in their history. It acknowledges that God did not forget them in their distress, but instead remembered them and provided for them.

The concept of mercy is central to this verse, as it is to the entire Psalm. The mercy of God is portrayed as enduring forever, emphasizing the eternal nature of God's compassion and grace. This idea is repeated throughout the Psalm, reinforcing the message that God's mercy is constant and unwavering, regardless of the circumstances.

The context of Psalms 136 is important for understanding the significance of verse 20. The Psalm is a hymn of praise and thanksgiving, likely intended for use in public worship. It would have been recited or sung by the community of Israel as a way of expressing gratitude for God's actions on their behalf. The repetition of the refrain "for his mercy endureth for ever" would have served as a reminder of God's faithfulness and a call to faith and trust in Him.

The Psalm is also grounded in the historical experiences of Israel, recounting various acts of God on their behalf, including the creation of the world, the deliverance from Egypt, and the conquest of the promised land. These acts serve as a reminder of God's power and faithfulness, and the Psalm functions as a kind of communal testimony to God's goodness.

Symbolism plays a significant role in this verse and the Psalm as a whole. The "low estate" of the Israelites can be seen as a symbol of any situation of need or desperation. It represents the human condition of vulnerability and suffering, and God's remembrance of them serves as a symbol of His care and concern for His people.

The enduring nature of God's mercy is also a powerful symbol, conveying the idea of God's eternal and unchanging love. This stands in contrast to the transient nature of human existence, and offers hope and comfort to those in need.

In sum, Psalms 136:20 is a powerful expression of faith and gratitude, celebrating God's mercy and faithfulness to His people. Its themes of suffering, remembrance, and enduring mercy are deeply resonant, and its symbols convey profound truths about the nature of God and His relationship with humanity. The verse serves as an invitation to trust in God's constancy and to offer praise and thanksgiving for His ongoing care and provision.