It is narrated in a mawquf form from Hazrat Salman bin Amir (may Allah be pleased with him) that when any one of you breaks his fast, he should do so with dates; if dates are not available, then he should break his fast with water, for water is purifying.
Hadith Referenceمسند احمد / مسند الشاميين / 17887
Hadith Gradingحکم دارالسلام:إسناد ضعيف لانقطاعه، حفصة لم تسمع من سلمان