Those workmen didn’t know what time the boss of that house was going to come home. He might come after the sun goes down, or he might come in the middle of the night, or he might come as the birds call out in the morning, or might come back after the sun comes up. You are like those workmen. You don’t know what time I will come back here and you have to be ready for me. So you have to keep looking out for me, like that guard at the gate has to keep looking out. Don’t get tired and sleepy.