The Prophet's Behaviour When Fasting

Each form of worship has its own adab (etiquette, decorum), and its adab is the secret of its acceptance.

The adab of fasting is evident in the Prophet's (peace be upon him) good character, which intensified during Ramadan. Ibn Abbas said, as recorded in Bukhari and Muslim, The Prophet was the most generous of all people and was more generous than usual during Ramadan Jibril used to meet him every night during Ramadan to teach him the Quran. The Prophet, when met by Jibril, would be better in virtue than the passing wind.

The scholars say that the increase in the Prophet's generosity during Ramadan is because of Allah's increase in generosity in giving unto his worshippers, since Allah grants unto his worshippers during Ramadan what He does not grant them outside of it. He beautifies for them the Jannah and doubles for them their reward and He frees many from the Fire.

The Prophet urged the Muslims to adopt good behaviour, thereby protecting the fast and doubling its reward. The Prophet said,

"He who does not give up uttering of falsehood and false acts, Allah is not in need of his abstention from food or drink."

This falsehood includes lies, slander, ridicule, theft, deceit, oppression and enmity. It is as if the Prophet in this hadith wants people's limbs and senses to fast.
In a hadith qudsi, the Prophet said,

"Fasting is a shield, so let not him who fasts behave immodestly nor engage in vulgar speech; and when someone abuses him or quarrels with him, let him say: `I am fasting, I am fasting`.

Source:"Ramadan with the Prophet" - Shaykh Atiyyah Muhammad Salim