Vincent's NT Word Studies
21. Dureth for a while (proskairov estin). Rev., endureth. Lit., is temporary: thus bringing out the quality of the hearer. He is a creature of circumstances, changing as they change. Wyc., is temporal, with explanation, lasteth but a little time.For (de). Rev. better, and, for the following clause does not give a reason for the temporariness, but adds something to the description of the hearer.
Tribulation (qliyewv). qlibw, to press or squeeze. Tribulation is perhaps as accurate a rendering as is possible, being derived from tribulum, the threshing-roller of the Romans. In both the idea of pressure is dominant, though qliyiv does not convey the idea of separation (as of corn from husk) which is implied in tribulatio. Trench cites, in illustration of qliyiv, pressure, the provision of the old English law, by which those who wilfully refused to plead had heavy weights placed on their breasts, and so were pressed and crushed to death ("Synonyms of the New Testament").
Robertson's NT Word Studies
13:21 {Yet hath he not root in himself} (ouk ecei de rhizan en heautwi). Cf. #Col 2:7 and #Eph 3:18 erriz"memoi. Stability like a tree. Here the man has a mushroom growth and "endureth for a while" (proskairos), temporary, quick to sprout, quick to stumble (skandalizetai). What a picture of some converts in our modern revivals. They drop away overnight because they did not have the root of the matter in them. this man does not last or hold out.
{Tribulation} (qliyews). From qlibw, to press, to oppress, to squeeze (cf. #7:14). The English word is from the Latin _tribulum_, the roller used by the Romans for pressing wheat. Cf. our "steam roller" Trench (_Synonyms of the N.T._, pp. 202-4): "When, according to the ancient law of England, those who wilfully refused to plead, had heavy weights placed on their breasts, and were pressed and crushed to death, this was literally qliyis." The iron cage was stenocwria.
