Matthew 22:4

‘Again he sent forth other servants, saying, “Tell those who are bidden, Behold, I have made ready my dinner. My oxen and my fatlings are killed, and all things are ready. Come to the marriage feast.'

When all was ready the patient king, expecting that they might well have had second thoughts when they had had time to realise the seriousness of what they were doing, sent further slaves. He was prepared to forgive them and give them another chance. This time his message was more urgent and demanding, and brooked no refusal. His mind was made up. The first meal of the feast (the word indicates the morning meal) was already in process of preparation (the marriage would as normal be at least a seven day event). The oxen and fatlings had already been killed. And everything else was prepared. They had no choice therefore but to come, or else to insult Him unforgivably.

We should note here that this was not just an invitation to a ‘party' as in Luke's parallel parable (Matthew 14:15), it was the demand of a king, who had the right to instant obedience from his subjects. They had to come to make submission to his son. To disobey would be treason.