Sayyiduna Ali (may Allah be pleased with him) narrates: When this verse was revealed: "And it is obligatory upon the people for the sake of Allah to perform Hajj to the House, for whoever is able to find a way thereto," the people asked: O Messenger of Allah! Is Hajj obligatory every year? The Noble Prophet (peace and blessings be upon him) remained silent. The people asked: Is it obligatory every year? The Noble Prophet (peace and blessings be upon him) said: "No, if I had said yes, it would have become obligatory." Then Allah revealed this verse: "O you who believe! Do not ask about things which, if made plain to you, may cause you trouble." In another narration, these words are mentioned: The people asked: Every year? The Noble Prophet (peace and blessings be upon him) remained silent. Then the people asked: Every year? The Noble Prophet (peace and blessings be upon him) said: After that, the narration continues as previously mentioned.