Ahmad b. Muhammad b. Yahya al-`Attar (rh) narrated to us. He said: My father narrated to us from Ya`qub b. Yazid from Ziyad b. Marwan al-Qindi from Abi Waki` from Abi Ishaq al-Sabi`i from al-Harith al-A`war from `Ali (as). He said
There is no good in lying nor in mockery, nor in promising your child something then failing to fulfill it. Lying leads to immorality, and immorality leads to the Fire. One of you may not stop lying until it is said: “he lies, and he has committed immorality.” One of you may not stop lying until there is not an iota of honesty in his heart, so he will be called a liar with Allah.