Main point summary
We should not be deceived in the midst of our trials into a distorted thinking about God. That is to say, we should not be led to believe that God is the one tempting us in our trials, but rather we ought to know that God gives only good gifts, especially the gift of our salvation.
The translation "God himself is without evil" is helpful here in explaining the relationship between 13d and 13e. *An alternative to General-Specific might be inference, but the inference is not so straightforward, because it does not follow that God is therefore not associated with evil in any way.
...when he is tempted,
Μηδεὶς... λεγέτω ὅτι
Let no one say...
ἀπὸ θεοῦ πειράζομαι •
“I am being tempted by God,”
ὁ γὰρ θεὸς ἀπείραστός ἐστιν κακῶν,
for God cannot be tempted with evil,
πειράζει δὲ αὐτὸς οὐδένα.
and he himself tempts no one.
ἕκαστος δὲ πειράζεται ὑπὸ τῆς ἰδίας ἐπιθυμίας
But each person is tempted
when he is lured
καὶ δελεαζόμενος •
and enticed by his own desire.
εἶτα ἡ ἐπιθυμία συλλαβοῦσα
Then desire x when it has conceived
gives birth to sin,
ἡ δὲ ἁμαρτία ἀποτελεσθεῖσα
and y sin when it is fully grown
brings forth death.
Μὴ πλανᾶσθε , ἀδελφοί μου ἀγαπητοί.
Do not be deceived, my beloved brothers.
πᾶσα δόσις ἀγαθὴ καὶ πᾶν δώρημα τέλειον ἄνωθέν ἐστιν καταβαῖνον ἀπὸ τοῦ πατρὸς τῶν φώτων,
z Every good gift and every perfect gift is from above, coming down from a the Father of lights
παρʼ ᾧ οὐκ ἔνι παραλλαγὴ ἢ τροπῆς ἀποσκίασμα.
b with whom there is no variation or shadow due to change. 1
c Of his own will
ἀπεκύησεν ἡμᾶς λόγῳ ἀληθείας
he d brought us forth by the word of truth,
εἰς τὸ εἶναι ἡμᾶς ἀπαρχήν τινα τῶν αὐτοῦ κτισμάτων.
e that we should be a kind of f firstfruits of his creatures.