I'm grateful for all the responses but I'm still sort of left feeling that the various suggestions have this problem: The translation is good Greek but bad English. IE: It is legitimate Greek but what does it mean? Where's the OT background? Or a confirmatory NT usage?
destitute of wealth of learning and intellectual culture which the schools afford (men of this class most readily give themselves up to Christ's teaching and proved them selves fitted to lay hold of the heavenly treasure)
Perhaps the reference to "in the spirit" was deemed necessary because not every poor person is thereby "saved" but rather he is speaking of those whose minds and attitudes are those of the poor, ashamed even to speak. In both Deuteronomy and Ezekiel Israel is chided because God found them poor, prodigally enriched them and then watched as they became "fat" and proud:
[Deu 32:12-16 KJV] 12 [So] the LORD alone did lead him, and [there was] no strange god with him. 13 He made him ride on the high places of the earth, that he might eat the increase of the fields; and he made him to suck honey out of the rock, and oil out of the flinty rock; 14 Butter of kine, and milk of sheep, with fat of lambs, and rams of the breed of Bashan, and goats, with the fat of kidneys of wheat; and thou didst drink the pure blood of the grape. 15 But Jeshurun waxed fat, and kicked: thou art waxen fat, thou art grown thick, thou art covered [with fatness]; then he forsook God [which] made him, and lightly esteemed the Rock of his salvation. 16 They provoked him to jealousy with strange [gods], with abominations provoked they him to anger.
[Eze 16:2 CSB] 2 "Son of man, confront Jerusalem with her detestable practices. (See https://www.blueletterbible.org/csb/eze/16/44/s_818044
This then links with, which Luke's version is very friendly with since he just says "Blessed are the poor":
[Luk 6:20-21 CSB] 20 Then looking up at his disciples, he said: Blessed are you who are poor, because the kingdom of God is yours. 21 Blessed are you who are now hungry, because you will be filled. Blessed are you who weep now, because you will laugh.
[Jas 2:1-9 KJV] 1 My brethren, have not the faith of our Lord Jesus Christ, [the Lord] of glory, with respect of persons. 2 For if there come unto your assembly a man with a gold ring, in goodly apparel, and there come in also a poor man in vile raiment; 3 And ye have respect to him that weareth the gay clothing, and say unto him, Sit thou here in a good place; and say to the poor, Stand thou there, or sit here under my footstool: 4 Are ye not then partial in yourselves, and are become judges of evil thoughts? 5 Hearken, my beloved brethren, Hath not God chosen the poor of this world rich in faith, and heirs of the kingdom which he hath promised to them that love him? 6 But ye have despised the poor. Do not rich men oppress you, and draw you before the judgment seats? 7 Do not they blaspheme that worthy name by the which ye are called? 8 If ye fulfil the royal law according to the scripture, Thou shalt love thy neighbour as thyself, ye do well: 9 But if ye have respect to persons, ye commit sin, and are convinced of the law as transgressors.
[Mat 11:16-26 CSB] 16 "To what should I compare this generation? It's like children sitting in the marketplaces who call out to other children: 17 "We played the flute for you, but you didn't dance; we sang a lament, but you didn't mourn! 18 "For John came neither eating nor drinking, and they say, 'He has a demon! ' 19 "The Son of Man came eating and drinking, and they say, 'Look, a glutton and a drunkard, a friend of tax collectors and sinners! ' Yet wisdom is vindicated by her deeds." 20 Then he proceeded to denounce the towns where most of his miracles were done, because they did not repent: 21 "Woe to you, Chorazin! Woe to you, Bethsaida! For if the miracles that were done in you had been done in Tyre and Sidon, they would have repented in sackcloth and ashes long ago. 22 "But I tell you, it will be more tolerable for Tyre and Sidon on the day of judgment than for you. 23 "And you, Capernaum, will you be exalted to heaven? No, you will go down to Hades. For if the miracles that were done in you had been done in Sodom, it would have remained until today. 24 "But I tell you, it will be more tolerable for the land of Sodom on the day of judgment than for you." 25 At that time Jesus said, "I praise you, Father, Lord of heaven and earth, because you have hidden these things from the wise and intelligent and revealed them to infants. 26 "Yes, Father, because this was your good pleasure.
So for me the bottom line seems to be:
"Blessed are the poor in attitude for theirs is the kingdom of heaven"
Or something close to that. IE: Basically I'm agreeing with the most straightforward reading and the translations as far as the grammar goes but interpreting it a tad differently where the "spirit" is the "attitude". Read that way it seems consistent with:
* Greek grammar and word usage (I think)
* Luke's version
* other references to the poor in Matthew
* Moses and the prophets
* James, etc. when speaking of the poor
BDAG has this usage for πνεῦμα:
ⓒ spiritual state, state of mind, disposition ἐν ἀγάπῃ πνεύματί τε πραΰτητος with love and a gentle spirit 1 Cor 4:21; cp. Gal 6:1. τὸ πν. τοῦ νοὸς ὑμῶν Eph 4:23 (s. νοῦς 2a). ἐν τῷ ἀφθάρτῳ τοῦ ἡσυχίου πνεύματος with the imperishable (gift) of a quiet disposition 1 Pt 3:4.
Arndt, W., Danker, F. W., Bauer, W., & Gingrich, F. W. (2000). A Greek-English lexicon of the New Testament and other early Christian literature (3rd ed., p. 833). Chicago: University of Chicago Press.
If "attitude" doesn't work then I would resort to "destitute in their spirit" though that doesn't communicate that much to me, personally.
What I lack in youth I make up for in immaturity.