en_tn/mat/24/43.md

Jesus tells his disciples how to get ready for his return.

the thief

Jesus is saying he will come when people are not expecting him, not that he will come to steal.

he would have been on guard

"he would have guarded his house" to keep it safe

and would not have allowed his house to be broken into

"he would not have allowed anyone to get into his house to steal things" (See: rc://en/ta/man/translate/figs-activepassive)