Only Luke had Jesus remark that this slave said (καὶ εἶπεν ὁ δοῦλος) to his master, calling him lord (Κύριε), that he had done what he had asked or commanded (γέγονεν ὃ ἐπέταξας). He had invited the poor, the crippled, the blind, and the lame, but there was still room (καὶ ἔτι τόπος ἐστίν). There is nothing like this in Matthew. Have you ever gone to an event that was not full?
Luke uniquely has Jesus explain why inviting the poor, the lame, the crippled, and the blind was a good thing to do. Jesus said that they would be blessed, happy, and fortunate (καὶ μακάριος ἔσῃ). These unfortunate people would not be able to repay them with another reciprocal dinner party, (ὅτι οὐκ ἔχουσιν ἀνταποδοῦναί σοι). However, they would be repaid (ἀνταποδοθήσεται γάρ σοι) at the resurrection of the righteous (ἐν τῇ ἀναστάσει τῶν δικαίων). In other words, they would receive a heavenly reward at the end times. They should not be that concerned about getting an earthly reward of another dinner invitation, when an eternal reward was available. Will you be blessed now or at the resurrection of the righteous?
Luke uniquely indicated that Jesus had other plans about dinner guests. When anyone gave a dinner party or feast (ἀλλ’ ὅταν δοχὴν ποιῇς), Jesus listed the people who this Pharisee should invite (κάλει), the poor (πτωχούς), the crippled (ἀναπήρους), the lame (χωλούς) and the blind (τυφλούς). These were not the elite of society who would get the higher places because of their distinguished positions. Do you know anyone who invites these kinds of people to a dinner party?