“There will be the weeping and the gnashing of teeth, when you shall see Abraham, and Isaac, and Jacob, and all the prophets, within the Kingly Rule of God, and yourselves cast forth outside.”
Those who have found the door closed against them will then have the chagrin of seeing all those whom they had previously honoured entering as faithful servants (Luke 12:44) into the heavenly Kingly Rule of God, while they themselves are cast out and put with the unfaithful (Luke 12:46). They will be in such anguish at it that they will ‘weep and gnash their teeth' (not here a picture of Hell, but of deep and unbearable disappointment). Some, however, see it as gnashing their teeth in anger at the One Who had done this to them, as they ‘look in through the door that was closed against them' and see what they have missed. But it is likely that we have now moved on from the parable (and besides the door was closed).
‘Weeping and gnashing of teeth.' Weeping expresses sorrow and regret (see Luke 6:25; Acts 20:37; James 4:9; James 5:1), the gnashing or grinding of the teeth pictures anger and hatred (compare Job 16:10; Psalms 35:16; Psalms 37:12; Psalms 112:10; Lamentations 2:16; Acts 7:54)
‘Abraham, and Isaac, and Jacob, and all the prophets.' Apart from Jesus and possibly John the Baptiser they had honoured the memory of all these great men. But while they honoured the faithful servants, they did not honour the lord of the house. It is their rejection of Jesus which has sealed their fate. It is no good looking back to figures of the past if we ignore the One Who towers above them all and Who is present with us to save. Their chagrin would be increased by the fact that they had always considered themselves to be sons of Abraham and therefore heirs of his promises, and now they were to be excluded from them.
‘Yourselves cast forth outside.' The fact that they are ‘expelled' demonstrates that this is not talking about the door that they refused to go through, or the door that was shut against them. As they had not passed through those they could not be ‘thrust forth' from them. So these words are not to be seen as a continuation of the parable, but rather as an explanation of the consequences. They will be thrust out from any hope when they face judgment on their future, as with the servant in the parable (Luke 12:46).