Sayyiduna Ibn Mas'ud (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "It is extremely bad for any man among you to say, 'I forgot such and such verse,' rather he should say, 'Such and such verse was made to be forgotten by me.'"
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 4288