When someone wakes up in the morning, but the body isn't fully rested. So, to compensate, the person takes a nap before actually starting their day.
Him: Hey babe you messaged me at 6am, but when I replied no response?
Her: Sorry babe, took my morning nap, but now I feel much better.
Him: Oh damn you're right, let me get my morning nap in as well! Talk to you soon.