Sayyiduna Ibn Mas'ud (may Allah be pleased with him) used to say that it is not permissible to lie in any case, whether seriously or in jest, and no person should make a promise to a child that he does not intend to fulfill. And the Prophet (peace and blessings of Allah be upon him) said to us: "A person continues to speak the truth until he is recorded with Allah as a truthful one (Siddiq), and likewise, a person continues to lie until he is recorded with Allah as a liar (Kadhdhab)."