Sabja seeds also called as tukumaria or sweet basil seeds are commonly used for falooda, sherbet and in other Asian drinks. It is believed in India that they help to beat the summer heat, keeping the body cool. Due to the gelatinous nature when soaked, they help in cleaning the walls of the stomach, help to regulate the bowel movements and flush the toxins from the stomach. Some folks get dehydrated fast in summer and get constipated especially kids, for them a drink made of these seeds is very beneficial.
these seeds can be used in sherbets and drinks made with any fruit like watermelon juice, lemonade, and cucumber juice or even with tender coconut water. Use rock sugar, also called as kalkanda in telugu as it is considered to be a better sweetener for summer. I do not know the exact reason why rock sugar is favored in Ayurveda especially during summer. In our families we consider rock sugar to have a cooling effect on the body and best to use in summer.
Though I prefer to eat my fruits as is, sometimes a fruit in the form of juice definitely makes sense on a hot day, keeping refreshed and hydrated.