Exegesis:

ekei estai ho klauthmos kai ho brugmos tōn odontōn ‘there will be the weeping and the gnashing of teeth.’ ekei may have local or temporal meaning, preferably the former, since v. 28a is a well known description of the place where the rejected are after the final judgment (cf. Mt. 8.12). The weeping and the gnashing of teeth may express contrition and anxiety, or anger because of being excluded from the kingdom of God to which they thought themselves to be entitled, preferably the latter (cf. Grundmann).

klauthmos ‘weeping,’ ‘crying.’

brugmos ‘gnashing,’ ‘chattering.’

hotan opsesthe … en tē basileia tou theou ‘when you see … in the kingdom of God,’ i.e. when you see that they have entered and are now in the kingdom of God. As v. 29 shows the reference is to a banquet in the kingdom of God.

humas de ekballomenous exō ‘but (when you see) yourselves being thrown out,’ i.e, when they try to get in they are excluded.

Translation:

Weep, see 6.21; Tzeltal uses a reciprocal form suggesting crying over one’s state.

Gnash your teeth. In several languages (e.g. Tzeltal, Shona, Kele, Toraja-Sa’dan) ‘to gnash/grind/bite one’s teeth’ has the required associations, but in others it suggests illness, or the enduring of pain without flinching, etc. In such cases one will better add an indication of the function, e.g. ‘because you are angry,’ ‘to show (your) anger,’ or shift to a cultural equivalent, as done in Yao, which uses a reference to a grimace that in English can be described as ‘clenching the teeth,’ or, ‘biting the tongue,’ as in a war-snarl of rage.

For Abraham see 1.55.

Kingdom of God is locative here; hence ‘the settlement where God rules’ (a San Miguel El Grande Mixtec dialect).

You yourselves thrust out, or, “kept outside” (Good News Translation), “shut out” (Phillips), or, ‘that you yourselves have to stand/remain outside.’ The verb ‘to see’ may have to be repeated, cf. e.g. Sranan Tongo, ‘you shall see how they chased you yourselves outside,’ cf. also Bible de Jérusalem.

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.