A faithful trustworthy person will never hold himself back from saying the truth even if by doing so he will receive embarrassment and denigration as in proportion to the severity of the sin of falsehood and the magnitude of its punishment it is far better to be embarrassed in this world and not be shamed in the next. The rule of this matter is that truth is foundation stone of the entire structure and one who keeps to it will find favor and be considered of good sense in the eyes of Hashem and mankind. However, on the other hand, falsehood is bad for heaven and bad for the creations, bad both in this world and in the next.
Chazal already warned us that a person should not say to a child that he will do a certain thing for him or will buy him a certain present when he does not intend to do so in order that children will not learn to lie. One must be extra careful to stand guard over one’s students and children to make sure that they do not learn to lie. Even if a child does something wrong if he admits the truth do not punish him. Instead, rebuke him and tell him not to repeat his iniquity, whereas if he lies you should punish him so that maybe there will be hope that he can educate the child on the correct and true path and then even when he grows older he will not deviate from it.
It is well-known that the sin of one who makes someone else sin is very great and it follows that one must be very careful not to ask someone else to tell one something which might be a secret that he holds and he does not want to reveal it as because of embarrassment he will come to tell a falsehood and invent something else.
Similarly, one should not request from another person to lend him something about which there is a possibility that he does not want to lend him as through the shame he will come to lie and say that he does not have one.