‘And he said, “I pray you therefore, father, that you would send him to my father's house, for I have five brothers, that he may testify to them, lest they also come into this place of torment.” '
Again this is not to be taken literally. Talking about the rich man as still having some good about him because he is concerned for others is irrelevant, for this is simply putting over in vivid picture form the fact that if men will not listen to the word of God, they will heed nothing. (In fact if we press the detail he still sees Lazarus as someone who is there in order to do as he is told and to see to his desires). This is accomplished by means of a fictional conversation between Abraham (whose voice crosses the great gulf!) and the rich man (whose voice, that of a disembodied spirit, does the same).
Putting it less picturesquely it is Jesus' way of making clear what the responsibility is, of the rich man's still living brothers, and of the Pharisees, and of all men. It is to recognise that they will get no voice from the dead beyond the grave (apart from the One Who will rise from the dead) and that they must therefore take heed to the voices put in this world by God.
‘Five brothers.' The number ‘five' is the number of covenant. (Compare the feeding of the five thousand). These five brothers represented Israel who always sought signs. But God will give them no further signs, for they have already received them in the Law of Moses. Why do they need signs when that book contains signs galore, and they ignore them? Why do they need to be told what to do, when God has already told them what to do and they disobey Him?