Answer

Yes, generally you may drink water before doing Ekasana, depending on the specific vow or rule you are following.

Explanation

In Jain practice, Ekasana usually means eating only once in one sitting during the day. Water rules may vary by tradition, family practice, or the guidance of a Guru.

Commonly:

• You may drink water before the Ekasana meal.
• Many people drink only properly filtered/boiled water according to Jain practice.
• Once you begin the Ekasana meal, you should complete eating in one sitting without getting up.
• Some stricter forms of tapas may have additional restrictions on water.

Spiritual Understanding

The purpose of Ekasana is to practice self-control, simplicity, discipline, and reduction of attachment to food. Water should also be taken mindfully, with respect for the vow being observed.

Takeaway

For regular Ekasana, drinking water before the meal is usually allowed, but if you have taken a specific vow, follow the rule given by your Guru or family tradition.