Matthew 22:1-14: "1 And again Jesus spoke to them in parables, saying, 2 'The kingdom of heaven may be compared to a king who gave a wedding feast for his son, 3 and sent his servants to call those who were invited to the wedding feast, but they would not come. 4 Again he sent other servants, saying, "Tell those who are invited, See, I have prepared my dinner, my oxen and my fat calves have been slaughtered, and everything is ready. Come to the wedding feast." 5 But they paid no attention and went off, one to his farm, another to his business, 6 while the rest seized his servants, treated them shamefully, and killed them. 7 The king was angry, and he sent his troops and destroyed those murderers and burned their city. 8 Then he said to his servants, "The wedding feast is ready, but those invited were not worthy. 9 Go therefore to the main roads and invite to the wedding feast as many as you find." 10 And those servants went out into the roads and gathered all whom they found, both bad and good. So the wedding halls was filled with guests.
"11 'But when the king came in to look at the guests, he saw there a man who had no wedding garment. 12 And he said to him, "Friend, how did you get in here without a wedding garment?" And he was speechless. 13 Then the king said to the attendants, "Bind him hand and foot and cast him into the outer darkness. In that place there will be weeping and gnashing of teeth." 14 For many are called, but few are chosen.'"
Revelation 19:9: "And the angel said to me, 'Write this: Blessed are those who are invited to the marriage supper of the Lamb.' And he said to me, 'These are the true words of God.'"
Revelation 19:17: "Then I saw an angel standing in the sun, and with a loud voice he called to all the birds that fly directly overhead, 'Come, gather for the great supper of God,'"
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I'm not sure that any of these passages are the best citations for this hymn. The parable of the wedding feast in Luke 14 is more relevant than the parable from Matthew 22 is. In Luke, Jesus says, "'But when you are invited, go and sit in the lowest place, so that when your host comes he may say to you, "Friend, move up higher." Then you will be honored in the presence of all who sit at table with you.'" (verse 10). This seems to be what the hymn references in the lines "You see my sin yet seat me at Your table; / Lord, as a guest, I surely am the least" in the third verse. Revelation 19:9 has some applicability here, but "the great supper of God" in Revelation 19:17 is quite different. The following verses explain that at this feast, the birds are eating the flesh of the unrighteous who rebelled against God.
There are references to the Lord's Supper in the first verse ("As from this altar we are here receiving / Your body and Your blood to make us whole") and in the fifth verse ("Heavenly Bread, my life and benediction, / This cup You give can take away each ill"). Any of the Words of Institution (Matthew 26:26-28, Mark 14:22-24, Luke 22:19-20, 1 Corinthians 11:23-25) could be cited for these. The title "Heavenly Bread" in the fifth verse is drawn from John 6:35, 38.
