Jeremiah 6:21

Therefore thus saith the LORD, Behold, I will lay stumblingblocks before this people, and the fathers and the sons together shall fall upon them; the neighbour and his friend shall perish.

Stumblingblocks - instruments of the Jews' ruin (cf. , "Whosoever shall fall on this stone shall be broken;" , "A stone of stumbling, and ... a rock of offence to both the houses of Israel;" ). God Himself in judicial displeasure ("I") lays stumblingblocks before the reprobate, "even as they have not liked to retain God in their knowledge" (; ; ). So His righteous sentence on the Jews, who turned their very spiritual privileges into means of spiritual pride, ending in their rejection of Messiah, was, "Let their table (the rich spiritual board provided for them) be made a snare, and a trap, and a stumblingblock unto them."

I will lay stumblingblocks before this people, and the fathers and the sons together shall fall upon them; the neighbour and his friend shall perish - indiscriminate ruin.

Fall upon them - stumble over them to their hurt.