Theophylact of Ohrid
Catena Aurea · Johannesevangelium 11
When he had heard therefore that he was sick, he abode two days still in the same place where he was. Then after that saith he to his disciples, Let us go into Judæa again. His disciples say unto him, Master, the Jews of late sought to stone thee; and goest thou thither again? Jesus answered, Are there not twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world. But if a man walk in the night, he stumbleth, because there is no light in him. Then after that saith He to His disciples, Let us go into Judæa again.
Some understand the day to be the time preceding the Passion, the night to be the Passion. In this sense, while it is day, would mean, before My Passion; Ye will not stumble before My Passion, because the Jews will not persecute you; but when the night, i. e. My Passion, cometh, then shall ye be beset with darkness and difficulties.