This is turning into a series: (B1) Happy are the beggars before the Spirit, because theirs is the kingdom of heaven. (here, here and here) (B2) Happy are those who lament, because they'll be called in and comforted. (here) (B4) Happy are those who hunger and thirst to be just before God, because they'll be well fed. (here)
Look up the next four yourself, but here's what I've got. (The ancient sense of mercy as pity is especially interesting.)
B3-Happy are the gentle, because they stand to inherit the earth.
B5-Happy are the pitiful, because they will receive pity.
B6-Happy are those who are clean all the way to the heart, because they will see God.
B7-Happy are the peacemakers, because they will be called sons of God.
Now... this last one is surprising... "persecuted" [diwkw]. If you go all the way back, back, back to line 1 in the Lexicon entry, the original meaning is something like cause to run, chase or pursue. It can also mean banish or drive away. I must once again emphasize my linguistic ignorance here, but I must also note that, once again, the beatitude rendering gets its own gloss at the bottom of the Liddel Scott entry (alongside John 5:16).
I just don't understand "persecuted" here. It definitely seems more appropriate in the context of vs.11 & 12, but in Matt.5:10, it comes in as a stand alone thought. My sandbox suggestion is to consider hound - "hounded because of righteousness". That's not in the lexicon, but it seems to split the difference well enough between the root and its ultimate rendering; now, check out Mt.5:44, 10:23 & 23:34 with hound, pursue, and/or banish in mind.
I also wonder about the legal option. L&S say diwkw can be prosecute, impeach, indict or accuse. I don't see that connection clearly yet, but I'm looking for it because the sentence ends with righteousness/justice. In the end, this looks like another deliberate multiple meaning from Jesus, like summon/comfort in v.4. The irony is too rich not to be there.
Happy are those who are prosecuted for being just. They'll get a Kingdom that is someplace else.
I'm also tempted to just be completely interpretative with the possessive case, here.
Happy are those who are hounded for being right with God. OF THEM is the Kingdom of heaven.
[Greek Grammar Alert: On that last one, I probably need to upgrade my understanding of of. ;-) But still.]
One last thought... who do we know that was hounded for his righteousness? Hounded, chased, pursued, accused, indicted, prosecuted? All those things happened for several years, in Judea & Galilee. But it was not only the authorities who pursued him. Along with them, it was also the crowds who pursued him, because of his righteousness. And from them, He brought down the Kingdom of Heaven. And TO them, He WAS the Kingdom of Heaven.
Just some more things to consider, at least...