This idea can be explained in terms of the verse, --"Moreover, the Eternal One of Israel will not lie nor change His mind, for He is not a man that He should change His mind."
A change of mind is possible only in [the spiritual composition of] a man.
Man's [conscious] faculties comprise intellect and emotion, the emotions being governed by the intellect and the intellect being related to the emotions.
On this level, a change of mind is possible, such as -- in the realm of emotions -- a change from kindness to severity or from severity to kindness.
If at first one's understanding dictates that one experience feelings of love, then love will result; if one's understanding then dictates otherwise, one will then change one's attitude from love and closeness to distance.
A similar change is imaginable in the opposite direction.
At any rate, we see that a change of feelings results from a change in understanding.
In the spiritual realm, change is likewise possible in the Divine emotive attributes.
[Regarding the generation of the Flood, for example,] it is written, --"And it grieved Him at His heart, and G-d said, `I will destroy [man].'"
This is an expression of stern judgment.
Later, however, there was a change to the attribute of mercy, as it is written, -- "I shall never more curse [the earth...] nor shall I ever again smite [every living thing]."
This change from strict justice to kindness came about through reason, which first determined guilt and then determined innocence.
Change is also possible in the Divine intellectual attributes.
[In the first instance, G-d brought on the Flood for a reason:] -- "All the impulse of the thoughts of his heart was only evil."
This reason necessitated a reaction in the Divine emotive attributes: it activated the attribute of strict justice.
Afterwards, the reason changed: -- "For the impulse of man's heart is evil from his birth."
This change dictated that the attribute of mercy be applied.
This change [in intellect] was brought about by a change in will.
The will itself also includes an emotive element, the emotions of the will.
The hidden reason that motivated the intellect to change from one reason to another on the same grounds (as is explained elsewhere) is dependent on the will.
In the meantime, --"G-d smelled the pleasing smell," and a new will was drawn down, for "the mystery of the sacrifices ascends to the mystery of the Ein Sof."
A change of will and regret thus became possible.
This, however, is possible only in a spiritual structure resembling that of man [i.e., only in those levels of Divine light that have descended and become enclothed, as in man], in intellect and emotions, with a transcendent light encompassing the intellect.
Concerning the innermost aspects of Keser, however, it is written, --"There is no left side in Atik."
At this level of Divinity there are no emotive attributes and no hidden reason; this level transcends any comparison to the spiritual structure of man. Of this level it is written, "He is not a man that He should change His mind." Here, change of mind and regret do not apply.