Luke 22:46—And He said to them, Why are you sleeping? Rise up and pray that you may not enter into temptation.
1 Thes. 5:5-6—For you are all sons of light and sons of the day. We are not of the night nor of darkness. So then let us not sleep, as the rest do, but let us watch and be sober.
For further reading please refer to 李常受文集，一九八〇，, vol. 1, “Perfecting Training,” ch. 14, p. 160.