Sister Purmul reminds us that fasting is not only abstaining from food and drink. She discusses the sources of ill speech and how they can be countered.
What I've learnt is that the one who does not leave false speech or false action, Allah SWT does not need anyone to leave his/her food and drinks. So backbiting could ruin our fast. 3 roots of ill speech are:
1. Not to be suspicious or not to spy (ill thoughts whispered by syaitan) so do not transgress your muslim brother/sister in thought or action
2. Unnecessary talking (cultivate good speech as there is no vain speech in Jannah)
3. Not intentionally practise good speech in regular conversation
May Allah SWT bestow upon us 'clean tongues' (good speech all the time), insya Allah!