What does Psalm 118:1 mean?

The psalmist cites the Lord's goodness and steadfast love as reasons to praise Him. This involves the term hesed, implying a loyal, consistent care (Exodus 34:6). The song leader may have spoken or sung the initial words, so the people in a congregation would deliver the repeated phrase. The first and last verses of this psalm are identical.

If this psalm were sung to commemorate the completion of the rebuilding of Jerusalem's walls around 444 BC, the people would recognize how good God had been to enable them to complete the project. Throughout Israel's history the Lord had been good to His people. Though He allowed them to suffer consequence and discipline, His love had never failed. He blessed Abraham, Isaac, Jacob, and Joseph (Exodus 2:24). He had delivered the Israelites from Egypt (Exodus 12:41) and had provided miraculously for them during their wilderness wanderings (Exodus 16:12; 17:6). He had given them Canaan, the Promised Land (Deuteronomy 1:8). He had rescued them from oppressing enemies in the era of the Judges (Judges 2:16–19). He had watched over the king, David, and had freed them from the Philistines (1 Samuel 17:50–51).

This song may have been written to celebrate Israel's return from captivity. The Lord enabled them to rebuild the temple and walls (Ezra 2:1; 3:1–2, 8). The nation had good reason to thank the Lord for His goodness and steadfast love!