Question:
If one has a choice b/w davening SE sitting down due to weakness, but not eating before davening, versus eating something and davening standing up, which should he do?
Answer:
It is preferable to eat before davening and daven normally standing up. Since he is not eating out of haughtiness but because of weakness.
Sources:
O:CH 89:3 Mishnah Berurah 22
