The Prophet (may Allah's peace and blessings be upon him) used to break his fast before praying by having three fresh dates
Good hadithعن أنس بن مالك رضي الله عنه قال: كان رسولُ اللهِ صلى الله عليه وسلم يُفطِر قبْل أن يصلي على رُطَبات، فإن لم تكنْ رُطَباتٌ فَتُمَيْراتٌ، فإن لم تكنْ تُمَيْراتٌ، حَسَا حَسَواتٍ مِن ماء.
Anas ibn Mālik (may Allah be pleased with him) reported: The Prophet (may Allah's peace and blessings be upon him) used to break his fast before praying by having three fresh dates. If there were no fresh dates, he would have dried dates; and if there were no dried dates, he would drink a few sips of water.
Explanation
Anas (may Allah be pleased with him) said that the Prophet (may Allah's peace and blessings be upon him) used to break his fast by eating fresh dates before the Maghrib prayer. However, when fresh dates were not available, he would have dried dates; and if there were no dried dates, he would drink a few sips of water. Having dates or water before eating is suitable because the stomach of a fasting person is empty, so he does not start with rich food as this may harm him.
Source · Narrated by At-Termedhy - Narrated by Abu Daoud - Narrated by Ahmad
From the Hadith Encyclopedia (hadeethenc.com).