Exegesis:
ho de akousas kai mē poiēsas ‘but he who has listened but not done,’ or, ‘but he who hears but does not do’ (treating the aorist as gnomic, i.e. expressing a general truth). The former rendering is preferable.
anthrōpō oikodomēsanti oikian epi tēn gēn chōris themeliou ‘a man who built on the ground without foundation,’ i.e. without digging at all and without laying any foundation. chōris.
hē proserēxen ho potamos ‘against which the river broke.’ hē refers to oikian.
kai euthus sunepesen ‘and immediately it collapsed.’ sumpiptō.
kai egeneto to rēgma tēs oikias ekeinēs mega ‘and the ruin of that house was great.’ mega is used here in a qualifying sense. Its position at the end is emphatic.
rēgma ‘ruin,’ i.e. the collapsing. It refers to the same event as sunepesen.
Translation:
Who hears and does not do them, or, ‘who has listened to my words and has not done them.’ The aspect is momentaneous, as against the durative aspect in v. 47.
Who built a house on the ground without a foundation, the opposite of “who dug … upon rock”, but worded more briefly. On the ground, or, ‘simply on the ground/soil,’ i. e. without any digging (Malay, Sranan Tongo), ‘not at all deep the holes for his posts’ (Tboli). Without a foundation, or, ‘but had not made a foundation/basis (for it),’ ‘not having founded it, or, set it on a solid layer underneath.’
Against which the stream broke …, usually better in a new sentence, e.g. ‘The flood/river broke against it and immediately it fell,’ cf. also “when the flood hit that house it fell at once” (Good News Translation).
The ruin of that house was great, or, ‘the total destruction of that house took place’ (Marathi), ‘it fell down, or, was destroyed, completely’ (cf. Trukese, East and Toraja-Sa’dan).
Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.