Ezekiel 14:3

set up their idols in Lit. have laid their idols upon their heart, which appears to mean, laid them on their minds, busied their thoughts and filled their affections with them.

stumblingblock of their iniquity The reference is still to the idols. Stumblingblock of iniquity is that over which one falls and commits iniquity, see on ch. Ezekiel 7:19.

before their face i.e. have placed them in their view, or, so as to follow them; cf. Ezekiel 14:6 "turn away your faces from all your abominations;" Psalms 16:8; Psalms 101:3. The language is figurative, and does not imply literal setting-up of idols.

should I be inquired of Or, shall I let myself be inquired of? that is, shall I give an answer (through the prophet)? cf. Isaiah 65:1, where "inquired of" is parallel to "was found."