The text one sends when they wake up from a good night sleep, it is a text sent in response to a text sent to them the previous night, when they unknowingly fell asleep on a convertextion. Mostly sent to not be rude even though the most common response to the morning text will be "what?", because the person receiving the morning text does not remember the convertextion that conspired the previous night.
Guy 1: Hey, how did the fight with Jenny go last night
Guy 2: Oh shit, I totally fell asleep on her
Guy 1: Dude, just send her a morning text
Guy 2: Good idea