Didn't know this. What if I always get up that early?
You get up that early?
If you would, the whole reason you wouldn't be able to eat is because you are Mekabel the fast when you go to sleep (even if you aren't actually Mekabel it with your mind...) This being the case, (of waking up before the fast starts, you were never Mekabel the fast earlier, since you don't have in mind that You will be sleeping then... As opposed to ppl who usually don't get up that early, if they should happen to wake up early w/o making such a stipulation, it's too late to eat since you were already Mekabel the fast...
(My understanding,.. Correct me If I'm wrong...)