Sahl ibni Sa’d, may Allah be pleased with him, narrates:

As long as humans make haste in breaking fast (i.e. eating the evening meal in Ramadan), they continue with the good. (Bukhari, Sawm: 45; Muslim, Siyam: 48; Muwatta, Siyam: 6; Tirmidhi, Sawm: 13.)

Imam Malik heard Abdulkerim ibni Abi’l-Muharik say:

One of the deeds of the Prophet is to make haste in breaking fast, and to delay suhur (the meal eaten by fasting Muslims just before dawn). (Muwatta, Qasru’s-Salat: 46.)

When the time for breaking fast came (iftar), Prophet Muhammad, peace and blessings be upon him, would never delay his iftar, would break his fast quickly.

He would mention the hadith qudsi (statements narrated by the Prophet from Allah, other than revelation):

Among my servants, the ones I love most are those who break their fast quickly.

In another hadith, the Prophet (PBUH) said:

When you hear the adhan (call to the prayer, also means that the fast ends), if you have a glass of water in your hand, do not put it down before drinking it and thus breaking your fast.

These hadiths recommend that in Ramadan, once the evening adhan is issued, one should make iftar, i.e. should break one’s fast.