Not eating before Davening

Rebecca Peyser asks:

I was wondering, what's the deal with not eating before you daven, specifically on Shabbat? I know that you can't eat before kiddush, but I thought that that only kicks in after you daven. So where does not eating before you daven come from?

You are correct about not eating before kiddush, but there is also an additional prohibition to eat before davening shacharit, any day of the week. That comes from the gemara in Brachot 10b where the gemara explains the pasuk of "לא תאכלו על הדם" as meaning "לא תאכלו קודם שתתפלו על דמכם" meaning that one should not eat before he davens for his wellbeing. The gemara continues and says that one who eats or drinks and then davens is guilty of putting his own "pride" or importance before Hashem's. The Shulchan Aruch brings this down l'halacha in Orach Chayim 89:3 and says that one should not eat or drink before davening shemona esrai (referring to shemona esrai of shacharit.) The Shulchan Aruch gives the exceptions of cold water and food and drinks for the purpose of refuah (healing.)

So, the basic principle is not to eat before davening. Acharonim discuss various exceptions to this rule, and some allow tea or coffee with certain conditions (See Mishna Brura Orach Chayim 89:22.)

This is where the issue of kiddush comes in. If one is going to drink water before davening on shabbos morning, kiddush is not required before the water, because kiddush only kicks in after davening. Once a person has davened and his kiddush obligation kicked in, however, even water, wouldn't be allowed before kiddush. (See Shulchan Aruch Orach Chayim 289:1.)