They were, meaning: due to what they have of reverence for Him and love for Him, such that they are as if they are naturally inclined towards it. For the sake of emphasis, the attribution to them occurred twice. "A little of the night" which is the time of rest and the fulfillment of desires. The meaning is emphasized by the affirmation of "what" as it is said: "They do not sleep," meaning: they perform the act of sleeping, which is light and little sleep. So what do you think of what is beyond that? For the sentence confirms their sleeping, which is the sleep for rest and alleviation of fatigue and what negates it. The night is mentioned to establish the meaning; for sleep is at night. The meaning is that they spend most of the night awake and sleep little.