Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) was delivering a sermon, and he said: "O people! Allah has made Hajj obligatory upon you." Then a man stood up and asked: "O Messenger of Allah! Is it obligatory every year?" He asked this question three times, but the Prophet (peace and blessings be upon him) did not answer him. Then he said: "If I had said yes, it would have become obligatory, and if it had become obligatory, you would not have been able to perform it." Then he said: "Leave that which I do not mention to you as it is. Those before you were destroyed because of excessive questioning and differing with their prophets. When I command you to do something, do it as much as you are able, and when I forbid you from something, then abstain from it."