John Gill Commentary Matthew 24:50

"the lord of that servant shall come in a day when he expecteth not, and in an hour when he knoweth not," — Matthew 24:50 (ASV)

The lord of that servant
Not by redemption and grace, but by creation and profession; shall come in a day when he looked not for him, and in an hour
that he is not aware of :
suddenly and unexpectedly: such was his coming in wrath and vengeance on the Jewish nation; and such is his coming oftentimes by death; and such will be his coming at the day of judgment.