There is something very special in the manner in which the doctrine of God's mercy is taught in Scripture.
Observe that several words, nearly synonymous, are used to teach us the doctrine--such as merciful, gracious, long-suffering, pitiful, slow to anger. And not satisfied with the positive--the inspired writers use the superlative--very pitiful and very gracious!
Not content with the singular, 'mercy'--they adopt and employ the plural form--'mercies'. They speak of the mercies of God. Nor are they content with a simple plural--but they speak of these mercies as manifold. Yes, they speak of the multitude of His mercies. And to denote that there is nothing uncertain about these mercies, they speak of them as sure mercies. They also speak of them not only as many, but great! Yes--and great above the heavens! And they speak of the greatness of His mercies, in magnitude equal to what they are in multitude--many and great and sure mercies! Think of that!
They are not mere mercies--but tender mercies, and these mercies they speak of as original with God. They speak of Him as the Father of mercies! They take care to tell us that mercy is not accidental to God--but essential; they speak of it as belonging to him. Daniel goes further still. He says--"To the Lord our God belong mercies"--and 'forgiveness'? No! but 'forgivenesses'! You may say that is not proper grammar--but it is glorious doctrine!
There is another set of phrases they use--they speak of God as rich in mercy, plenteous in mercy, and full of compassion. They speak of His abundant mercy, of the earth as full of His mercy, to denote its amplitude. And in respect of its continuance, they say that His compassions fail not. In Psalm 136, twenty-six times it is said, "His mercy endures forever!"
There is still another phraseology used by the sacred writers. They speak of God's kindness, His great kindness, His marvelous kindness, His everlasting kindness. But they are not satisfied to speak of it as simple kindness; they call it merciful kindness, and speak of it as great towards us. They call it loving-kindness, also. And we read of God's marvelous and excellent loving-kindness, with which it is said also that He crowns us! Here, too, they use the plural form, loving-kindnesses; and they speak of the multitude of His loving-kindnesses.
We also find the sacred writers speaking of the mercy of God compared to certain human traits. For example, to a father's pity--which it is said to be like; and to a brother's friendship--than which it is closer; and to a mother's love--which it is said to exceed!
What more could they say?