Mat 5:12 Rejoice, and be exceeding glad: for great [is] your reward in heaven: for so persecuted they the prophets which were before you.
Alternative: Celebrate and celebrate some more! For what? Your great universal payment. Because they hounded the visionaries before you in the same way.
The word that is translated here as "reward" is misthos, which primarily means wages paid for work. It is the same word used in translating "wages of sin." And again, remember that the term used for "heaven" doesn't mean just the afterlife. It means the heaven, that is, the entire universe, the domain of God. So the phrase describes not a reward or prize but our just compensation from God both in this life and the next, in this world and heaven.
Christ is saying that living correctly is work. It is hard work that we get paid for in the big scheme of things. By mentioning the prophets, Christ is putting this work into historical perspective. The prophets may have been hounded and driven away, but they are now remembered and honored, not only by God, but in this world as well.
In other words, this world does recognize virtue, eventually. Over the long-term, virtue wins. This is true whether we think of the long-term as the course of a life or from life to afterlife.
"Rejoice" is from chairô (chairo) which means "rejoice," "take pleasure in," and "welcome."
"Be exceedingly glad" is from agalliaô (agalliao) means "rejoice exceedingly" and is a later from of agallomai,which means to "glorify," and "exalt," especially the idea of "paying honor" to God.
The first "for" is from hoti (hoti), which means "for what," and "wherefore." A form of hostis (hostis), which means "that," "any one who," "anything which," "whosoever," "whichsoever" and "anybody whatsoever."
"Great" is from polus (polys) which means "many (in number)," "great (in size or power or worth)," and "large (of space)." As an adverb is means "far," "very much," "a great way," and "long."
"Reward" is from misthos (misthos), which means "wages" in the sense of compensation for work done, "pay," "hire," "fee," "recompense," and "reward."
"Heaven" is from the Greek ouranos (ouranos), which means "heaven as in the vault of the sky," "heaven as the seat of the gods," "the sky," "the universe," and "the climate."
The second "for" comes from gar (gar) which is the introduction of a clause explaining a reason or explanation: "for," "since," and "as." In an abrupt question it means "why" and "what."
"So" is from houtôs (houtos), which means "in this way," "even so," "in the following way," "even as now," and "with this in view."
"Persecuted" is from diôkô (dioko), which means "to pursue," "to chase," "to urge on," or "to drive." It means "persecute" when used as a legal term.
"Prophet" is from prophêtês (prophetes), which means "one who speaks for a god and interprets his will," "interpreter," "keepers of the oracle," the highest level of priesthood in Egypt," "interpreter," and "herald."