It is narrated in a mawquf form from Sayyiduna Salman bin Amir that when any one of you breaks his fast, he should break his fast with dates. If dates are not available, then he should break his fast with water, for water is purifying.
Hadith Referenceمسند احمد / مسند المدنيين رضي الله عنهم اجمعين / 16225