It is the female counter point to;

Matthew 24:45-51:
45"Who then is the faithful and wise servant, whom the master has put in charge of the servants in his household to give them their food at the proper time? 46It will be good for that servant whose master finds him doing so when he returns. 47I tell you the truth, he will put him in charge of all his possessions. 48But suppose that servant is wicked and says to himself, 'My master is staying away a long time,' 49and he then begins to beat his fellow servants and to eat and drink with drunkards. 50The master of that servant will come on a day when he does not expect him and at an hour he is not aware of. 51He will cut him to pieces and assign him a place with the hypocrites, where there will be weeping and gnashing of teeth.

And also explained:

Luke 12:35-38:
Watchfulness
35"Be dressed ready for service and keep your lamps burning, 36like men waiting for their master to return from a wedding banquet, so that when he comes and knocks they can immediately open the door for him. 37It will be good for those servants whose master finds them watching when he comes. I tell you the truth, he will dress himself to serve, will have them recline at the table and will come and wait on them. 38It will be good for those servants whose master finds them ready, even if he comes in the second or third watch of the night.

Delaying means, do not delay in your salvation in Christ.
The oil is good works - the foolish do not have sufficient good works.
We have to be ready for the Bridegroom at all times.
The belief that good works (charity, helpfulness) is needed.
The shut door means that admission is not automatic.