Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: A man asked the Prophet Muhammad (peace be upon him) in a loud voice,“Is Hajj obligatory every year?”The Prophet (peace be upon him) remained silent, then he said,“No! Rather, Hajj is obligatory upon a Muslim only once. If I had said every year, it would have become obligatory every year.”Then another man stood up and said,“Can I perform Hajj on behalf of my father, as he is an old man?”The Prophet (peace be upon him) said,“You may perform Hajj on behalf of your father.”