For years my body has had its internal clock set on waking up between 3 and 4 AM, no matter what time I turn in for the night. I used to fight it. I even went to the doctor for sleeping pills, but it made no difference. Finally, I decided to just accept the fact that this is how I am.
Billy Graham associated waking up in the early hours as a divine invitation to prayer, spiritual reflection, and for strengthening one’s relationship with God. And that is was the “quiet hours” seen as time free from daily distractions, allowing for deeper communion, intercession for others, and hearing God’s voice.
As the world sleeps, the mind is quiet, offering a unique opportunity to focus on God without the noises of the day.
From Pity to Praise 