Reflection on the The Parable of the Great Banquet
This parable operates on two levels, illustrating both the first and second coming of Christ, who is the servant sent to gather many. Supper indicates evening, the end of the age. The people invited are first the Jews, then all mankind.
Those in the streets and lanes indicate (1) the Gentiles who accepted Christ after the faithless Jews rejected Him, and (2) those outside the Church replacing those within who have rejected their own baptism.
The Fathers see the three excuses as having both a literal meaning, that many are too attached to worldly cares to accept the Kingdom of God (v. 26; 18:29), and spiritual meanings. St. Ambrose sees the three excuses of I cannot come representing the Gentile, the Jew, and the heretic. The Gentile's devotion to earthly wealth is represented by the piece of ground, the Jew's enslavement to the five books of the Law by the five yoke of oxen, and the heretic's espousal of error by the man refusing on account of his wife. Theophylact more generally associates the excuses with people devoted to earthly matters, to things pertaining to the five senses, and to all pleasures of the flesh.