The book of Psalm is split up into 5 books.
Psalm 41:13 is the end of “Book 1” of the Psalms. You can probably see that in your Bible. Right before Psalm 42 you probably see a heading saying that you’ve now entered Book 2 of the Psalms.
And we see each psalm that ends each book of the Psalms end with praise.
Psalm 72:19 ends Book 2 of Psalms and says “And blessed be his glorious name for ever: and let the whole earth be filled with his glory; Amen, and Amen.”
Psalm 89:53 ends Book 3 – “Blessed be the LORD for evermore. Amen, and Amen.”
Psalm 106:48 ends Book 4 and says “Blessed be the LORD God of Israel from everlasting to everlasting: and let all the people say, Amen. Praise ye the LORD.”
And last, Psalm 150:6 ends Book 5 with praise, “Let every thing that hath breath praise the LORD. Praise ye the LORD.”
Comparing how each book ends
So, the ending to the first 3 books of Psalms has this statement “Amen and amen!”
The end of Book 4 has “amen and praise the Lord.”
And then book 5 ends with “praise the Lord.”
Why does each book end the way it does?
So, it seems that what the psalmists are looking for is a voice to echo back their Amen and praise to the Lord! They assert that what has been said is trustworthy and reliable and true!
So, the Lord who is the God of Israel is blessed for ever!
Amen, I say to that!
And we all say in our hearts Amen to that, no doubt.