The Moment of Prevenient Grace in Paradise Lost

On the Milton listserve that I belong to, we've recently been discussing postlapsarian free will, i.e., the free will that Adam and Eve possess after the fall that enables them to accept or reject saving grace.

I inquired online about the precise moment when prevenient grace -- that grace preceding saving grace -- confers the power of free will on Adam and Eve.

One candidate for such a precise moment occurs in Paradise Lost 10.220-223. However, it does not clearly say so. In this passage, the Son of God has covered Adam and Eve with a robe of righteousness, which perhaps extends them no grace (whether prevenient or saving) and thus has no effect on their hearts but merely acts as a shield against the Father's judgement:

Nor he their outward only with the skins
Of beasts, but inward nakedness, much more.
Opprobrious, with his robe of righteousness,
Arraying, covered from his Father's sight. (PL 10.220-223)

Although inward nakedness receives a covering, the reason given only concerns hiding the opprobriousness of sin from the Father's sight.

But I wonder if something of grace doesn't begin here. The robe of righteousnes comes as a gift, undeserved and therefore characteristic of grace. And by 10.1087ff, even though Adam only contemplates repentance in his mind, he would seem to differ from Satan, who also contemplates repentance mentally but never quite accepts it even intellectually.

Adam and Eve who awaken from sleep after their rough, postlapsarian sex in 9.1046ff seem to me to be totally depraved in the Calvinist sense, by which I mean that they are unable to turn spiritual eyes onto their own faults but ever blame each other. This continues up to the scene of the Son's judgement in 10.103-208, where they continue to blame each other (and the serpent) but are pitied by the Son, who then extends to them in 10.220-223 the covering robe of righteousness. The scene then shifts away from Adam and Eve for some 500 lines.

When we next meet Adam, in 10.720ff, he is blaming not only Eve but also himself. Eve, in turn, blames herself (rather than the serpent). Her appeal to Adam in 10.914ff that he not reject her and his compassionate response in 10.937ff set the stage for their common appeal to God for forgiveness (cf. Mt. 5:23-24) but also imply, along with the self-blame mentioned, that some good alteration has already taken place in their hearts.

Isaiah 61:10-11 perhaps stands behind the "robe of righteousness" of PL 10.222:

10 I will greatly rejoice in the LORD, my whole being shall exult in my God; for he has clothed me with the garments of salvation, he has covered me with the robe of righteousness, as a bridegroom decks himself with a garland, and as a bride adorns herself with her jewels. 11 For as the earth brings forth its shoots, and as a garden causes what is sown in it to spring up, so the Lord GOD will cause righteousness and praise to spring up before all the nations. (Isaiah 61:10-11 (AV))

Since the robe of righteousness here in Isaiah 61:10-11 doesn't just cover but also causes righteousness and praise to spring up, then similarly, the robe of righteousness mentioned in PL 10.222 may therefore have a more intimate effect than simply that of covering. Perhaps it initiates the process of grace and could thus be seen as the moment that prevenient grace begins to have effect.

If so, then this might be the moment when postlapsarian free will comes to Adam and Eve.