"He sent his servants to those who had been invited to the banquet to tell them to come." Matthew 22:3

A double invitation was customary among the wealthy when giving entertainments.

The invitation was given some time in advance, as it is still done today, and then when the feast is ready a servant was dispatched with an announcement of the fact.

Esther invited Ahasuerus and Haman to a feast, and when it was ready, the king's chamberlains were sent to notify Haman (Esther 5:8; 6:14)

This custom also finds illustration in the parable of the banquet in Luke 14:16,17: "A certain man was preparing a great banquet and invited many guests. At the time of the banquet he sent his servant to tell those who had been invited, 'Come, for everything is now ready.'" Here, the two invitations are distinctly marked. Of interest in this example is the fact that the second invitation was given only to those who had accepted the first.