Every verse of Psalm 136 contains the word "mercy". Verse 1:
1O GIVE thanks to the Lord, for He is good; for His mercy and loving-kindness endure forever.
We have covered this word many times on the blog and it is a very powerful word! It is the Hebrew word "checed". This word means: kindness; goodness; faithfulness; loving-kindness; steadfast love; devotion. Here is a portion of what Vine's Expository Dictionary says about this word:
In general, one may identify three basic meanings of the word, which always interact: "strength," "steadfastness," and "love." Any understanding of the word that fails to suggest all three inevitably loses some of its richness. "Love" by itself easily becomes sentimentalized or universalized apart from the covenant. Yet "strength" or "steadfastness" suggests only the fulfillment of a legal or other obligation.
The word refers primarily to mutual and reciprocal rights and obligations between the parties of a relationship (especially Yahweh and Israel). But checed is not only a matter of obligation; it is also of generosity. It is not only a matter of loyalty, but also of mercy. The weaker party seeks the protection and blessing of the patron and protector, but he may not lay absolute claim to it. The stronger party remains committed to his promise, but retains his freedom, especially with regard to the manner in which he will implement those promises. Checed implies personal involvement and commitment in a relationship beyond the rule of law.
(from Vine's Expository Dictionary of Biblical Words, Copyright © 1985, Thomas Nelson Publishers.)
Shalom in Him!