Safeguarding As-Saum (The Fast)

Abu Hurairah (Radhiallaho anha) reported:

The Messenger of Allah (Sallallaahu 'alaihi wasallam) said,

"When any one of you is observing Saum (fasting) on a day, he should neither indulge in obscene language nor should he raise the voice; and if anyone reviles him or tries to quarrel with him he should say: `I am observing fast.'''

[Al-Bukhari and Muslim]