I lay down and slept;On a couple of occasions he welcomes in the dawn with praise. What is so exciting about a new day? I don't think David even had access to coffee. What did the morning have to offer him?
I woke again, for the Lord sustained me.
I suppose the key thing is that David has been asleep. Being asleep is the state of least control. Awake, David may be King and have followers at his beck and call. Asleep, he is absolutely vulnerable. Sleep is like a temporary death. So waking up is like... a resurrection?
The morning brings fresh mercies. The death of sleep has wiped out the sin of yesterday - but to rise from that sleep takes a new act of mercy. Putting yesterday to death doesn't necessarily lead to tomorrow. Fresh mercy, new life.
But fresh mercies are crowded out pretty quickly by fresh struggles, fresh disappointments, fresh sins, fresh troubles. Fresh, but old. They seem new, but they belong to yesterday's yesterdays. Not yet new, not totally. Morning becomes afternoon, and we long for sleep - to put the day with all its mess to bed. To die, to sleep.
And yet every moment could be a morning, rich with new mercy, springing unexpected from the grave of just now, the grave dug by Christ with his own cruciform shovel.
That is why it says:
“Awake, O sleeper,
and arise from the dead,
and Christ will shine on you.”