From the Douay-Rheims translation of the Holy Scripture:
And the Lord rained upon Sodom and Gomorrha brimstone and fire from the Lord out of heaven. (Genesis 19:24)
Why is the Lord distinguished from the Lord out of Heaven?
Since the 'trinity' tag is activated I am giving the trinitarian view on this passage.
And the neighbouring cities, Admah and Zeboim, as appears from Deu 29:23 Jeremiah 49:18 Hosea 11:8.
Brimstone is added to the fire, either to convey and carry down the fire, which in itself is light and apt to ascend; or to increase it, Isaiah 30:33; or to represent the noisomeness of their lusts.
From the Lord, i.e. from himself; the noun put for the pronoun, as Genesis 1:27 2 Chronicles 7:2. But here it is emphatically so expressed, either,
To signify that it proceeded not from natural causes, but from the immediate hand of God. Or,
To note the plurality of persons in the Godhead, God the Son, who now appeared upon the earth, rained from God his Father in heaven, both concurring in this act, as indeed all outward actions are common to all the persons of the Trinity.
Genesis 19:24. Then the Lord rained, from the Lord — The Son, who had conversed with Abraham, from the Father, for the Father has committed all judgment to the Son. He that is the Saviour will be the destroyer of those that reject the salvation.
I would just add to say how remarkable it is to see, firstly, the restraint of scripture in regard to that which cannot, in righteousness, be spoken of until the Son is manifested, in humanity ; and, secondly, yet to see also the hints of that revelation which is yet to come.
This passage, so astutely pointed out by the OP, reminds me of the incident at the burning bush where the angel of Jehovah appears in the flame, Jehovah sees Moses turn aside and Elohim speaks from the midst of the bush. See Biblehub Interlinear : threefold descriptive aspects.
So, here, the sensitive, almost ambiguous, wording 'Jehovah rained on Sodom and Gomorrah brimstone . . . . . and fire from Jehovah out of the heavens'. See Biblehub Interlinear
One active within the sphere of the earth with an earthly substance ; One active from the heavens with heavenly energy.
and Jehovah hath rained upon Sodom and upon Gomorrah brimstone and fire from Jehovah, from the heavens; Genesis 19:24 Young's Literal Translation
Added note : 'brimstone' is sulphurous which forms sulphur dioxide on combustion which, if breathed in, forms sulphuric acid in contact with the mucous membranes, thus acidically burning the inner parts of the breathing system ; nose, mouth, throat, trachea and lungs.
Thus the 'breath of God' given as atmosphere to all in goodness and grace, here, in judgment, turns to a burning torment.
Thus fire without and sulphur within, cause external and internal burning, just as will the lake of fire and brimstone, which is never quenched.