For their heart
leb (labe)
the heart; also used (figuratively) very widely for the feelings, the will and even the intellect
was not right
kuwn (koon)
to be erect (i.e. stand perpendicular); hence (causatively) to set up, in a great variety of applications
with him neither were they stedfast
'aman (aw-man')
to build up or support; to foster as a parent or nurse; figuratively to render (or be) firm or faithful, to trust or believe, to be permanent or quiet; morally to be true or certain
in his covenant
briyth (ber-eeth')
a compact (because made by passing between pieces of flesh) -- confederacy, (con-)feder(-ate), covenant, league.
