His seed
zera` (zeh'-rah)
seed; figuratively, fruit, plant, sowing-time, posterity -- carnally, child, fruitful, seed(-time), sowing-time.
shall be mighty
gibbowr (ghib-bore')
powerful; by implication, warrior, tyrant -- champion, chief, excel, giant, man, mighty (man, one), strong (man), valiant man.
upon earth
'erets (eh'-rets)
the earth (at large, or partitively a land) -- common, country, earth, field, ground, land, natins, way, + wilderness, world.
the generation
dowr (dore)
a revolution of time, i.e. an age or generation; also a dwelling -- age, evermore, generation, (n-)ever, posterity.
of the upright
yashar (yaw-shawr')
straight -- convenient, equity, Jasher, just, meet(-est), + pleased well right(-eous), straight, (most) upright(-ly, -ness).
shall be blessed
barak (baw-rak')
to kneel; by implication to bless God (as an act of adoration), and (vice-versa) man (as a benefit); also (by euphemism) to curse (God or the king, as treason)