Luke 14:20

“And another said, ‘I have married a wife, and therefore I cannot come.' ”

The third does not make excuses. He baldly rejects the invitation and states that as he is newly married he cannot be expected to leave his wife in order to attend the supper. His wife (or his begetting of an heir) means more to him than the one who has invited him, and in the final analysis, more than the Kingly Rule of God.

And yet it is an excuse for if need arose, such as a summons from the king, or a fire on his farm, he would certainly be ready to leave his wife for an evening, or even more than an evening. His refusal was a great insult. There was really no excuse for his not attending. It indicated his contempt for the invitation.

Note how the threefoldness of the excuses indicate that they cover all possible excuses, of which there would be many, for three indicates completeness (just as two will later indicate certainty of witness - Luke 14:21).