He that walketh
halak (haw-lak')
to walk (in a great variety of applications, literally and figuratively)
uprightly
tamiym (taw-meem')
without blemish, complete, full, perfect, sincerely (-ity), sound, without spot, undefiled, upright(-ly), whole.
and worketh
pa`al (paw-al')
to do or make (systematically and habitually), especially to practise -- commit, (evil-) do(-er), make(-r), ordain, work(-er).
righteousness
tsedeq (tseh'-dek)
the right (natural, moral or legal); also (abstractly) equity or (figuratively) prosperity -- even, (that which is altogether) just(-ice), (un-)right(-eous) (cause, -ly, -ness).
and speaketh
dabar (daw-bar')
perhaps properly, to arrange; but used figuratively (of words), to speak; rarely (in a destructive sense) to subdue
the truth
'emeth (eh'-meth)
stability; (figuratively) certainty, truth, trustworthiness -- assured(-ly), establishment, faithful, right, sure, true (-ly, -th), verity.
in his heart
lebab (lay-bawb')
the heart (as the most interior organ)