The reason for the sahaabah radiyallhu anhum wishing that Sayyidina Rasoolullah sallallahu alaihe wasallam should stop repeating it, is because of their love for Sayyidina Rasoolullah sallallhu alaihe wasallam, and there fear that he would become tired. It is enough to say a thing once. It could be possible that he might have become angry, or that in anger, Sayyidina Rasoolullah sallallahu aliahe wasallam might say something that would become a cause of loss to the ummah. Those who attend these type of religious or wordly assemblies are well aware of such situations. Sayyidina Rasoolullah sallallhu alaihe wasallam repeated it to show its importance. Lies and falsehood inevitably gets a person involved in adultery, murder and many other sins. Sayyidina Rasoolullah sallallahu alaihe wasallam also said, "When a person lies, the angels stay a distance of a mile away from him because odour it causes in person's mouth". He has also said, "A believer cannot be a liar". Sayyidina Abu Bakr Siddique radiyallahu Anhu says, "Stay away from lies, because lies keep away Imaan." (Al-Itidaal)