Albert Barnes Commentary Matthew 25:10

"And while they went away to buy, the bridegroom came; and they that were ready went in with him to the marriage feast: and the door was shut." — Matthew 25:10 (ASV)

Went in with him to the marriage. The marriage feast. The marriage ceremony took place before the bride left her father's house; but a feast was given at the house of her husband, and which was also called the marriage, or a part of the marriage solemnities. This part of the parable doubtless represents the entrance of those who are ready, or prepared, into the kingdom of God, when the Son of Man shall come. They will be ready who repent of their sins; who believe on the Lord Jesus; who live a holy life; and who wait for his coming. See Mark 16:16; John 5:24; Acts 3:19; Revelation 22:11; 2 Peter 3:11–12; 1 Timothy 6:17–19; 2 Timothy 4:6–8.

The door was shut. No more could be admitted to the marriage feast. So, when the truly righteous shall all be received into heaven, it will be closed against all others. There will be no room for preparation afterwards, Revelation 22:11; Ecclesiastes 11:3; Ecclesiastes 9:10; Matthew 25:46.