Psalm 118:2 NKJV
Let Israel now say, "His mercy endures forever."
This psalm makes a plea to Israel to verbalize a declaration about God's mercy. The next 2 verses repeats the plea to the house of Aaron, and then to those who fear the Lord. David said in Psalm 59:16 that he would sing about the mercy of God. Here the plea goes out to declare it. It is obvious that mercy was a major thing to celebrate among God's chosen people. So let's sing about it and let us declare it. Let us continually celebrate the mercy of God - the manifestation of His power on our behalf - a blessing that we could not earn. It is the Lord doing for us what only He could do because of His great love for us.