Reference: I’laam al-Mu’aasireen bi-Fataawa Ibn ‘Uthaymeen – Page 133
Question: Is the obligation of performing the hajj to be undertaken promptly [once all its conditions are met], or to be done at one’s convenience?
Response: That which is correct is that it is obligatory [to undertake the hajj] promptly; And it is prohibited for a person who is able to perform hajj to the Sacred House of Allaah to delay it. Likewise is the case with all of the legislated obligatory acts of worship, if they are not restricted by time or reason (cause), then it is obligatory [to undertake them] promptly.