Dear respected Shaykh, assalamu alaikum wa rahmatullahi wa barakatuh. What is false testimony? Does it invalidate fasting? ما هي شهادة الزور؟ وهل تبطل الصوم؟

Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions. Wa alaikum assalam wa rahmatullahi wa barakatuh. As to what follows: In response to your question, we say: This question is made up two sections. The first sections is on the reality of false testimony. False testimony is giving an untrue testimony and it is saying something which is contrary to the truth. This is the general meaning. False witness is also used to deprive people of their rights either in denying a debt, attaining benefit or other reasons. The Prophet (peace be upon him) considered this to be a major sin as is mentioned in an authentic hadith.  The Prophet (peace be upon him) said that polytheism, murder, disobeying parents were major sins, then he said, “And I warn you against giving forged statement and a false witness; I warn you against giving a forged statement and a false witness." [al-Bukhari (5976) and Muslim (88).   The second part of the question is about the effect of engaging in false testimony on fasting. Undoubtedly this reduces the reward of fasting. However, it does not invalidate fasting.  A Muslim should avoid such activities because the Prophet (peace be upon him) said, “Whoever does not give up forged speech and evil actions, Allah is not in need of his leaving his food and drink.” [al-Bukhari (1903)].