What is the meaning of the statement that mercy is of two kinds?

Question:
The one who transmitted from al-Muhallab that mercy is of two kinds said: Mercy as an attribute of the Essence, which does not multiply, and mercy as an attribute of action, which is the one referred to?

Answer:
This is correct; because His mercy as an attribute of His Essence is not a created thing, and it is an attribute of Him, like knowledge, power, and wisdom. These are essential attributes: al-Rahman, al-Rahim.
And mercy is a second type, which the Exalted and Majestic is He created, and He made it part of His general creation, by which He shows mercy to His servants. He sent down from it one mercy, from which came their compassion, mutual mercy, and cooperation, and what they obtained of food, drink, dwellings, air, and water. All of this is from His mercy (Glorified and Exalted is He) This is a created thing, and it is from the effects of His mercy, which is His attribute (Glorified and Exalted is He)... The created mercy is from the attribute of action, like creation.
Q: So, does he not mean the attribute?
The Shaykh: It is an attribute that arose from His action, from His creation (Glorified and Exalted is He) Just as He created creation and giving, these are attributes of action. And the mercy that subsists in Him is an essential attribute, subsisting in Him, like knowledge, which is an essential attribute, and power, which is an essential attribute.
Q: Is this division correct?
The Shaykh: Yes, there is nothing wrong with it. Some of them say that the criterion is: what is by choice and will, that is an attribute of action; and what is not related to will, that is called an attribute of the Essence, an essential attribute. So the created mercy arose from will. The essential attribute, which subsists in Him, the Exalted, is an essential attribute like knowledge, and is not related to will, like knowledge, power, the Face, the Hand, and the like of those which are essential attributes that are inseparable.