Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah ﷺ delivered a Khutbah and said, "O people! Hajj (pilgrimage to the House of Allah) has been made incumbent upon you, so perform Hajj." A man inquired: "O Messenger of Allah, is it prescribed every year?" He ﷺ remained silent till the man repeated it thrice. Then he ﷺ said, "Had I replied in the affirmative, it would have surely become obligatory, and you would not have been able to fulfill it." Afterwards he said, "Do not ask me so long as I do not impose anything upon you, because those who were before you were destroyed on account of their frequent questioning and their disagreement with their Prophets. So when I order you to do something, do it as far as you can; and when I forbid you from doing anything, eschew it."
وعن أبي هريرة رضي الله عنه قال: خطبنا رسول الله صلى الله عليه وسلم فقال: "يا أيها الناس إن الله قد فرض عليكم الحج فحجوا" فقال رجل: أكل عام يا رسول الله؟ فسكت، حتى قالها ثلاثًا فقال رسول الله صلى الله عليه وسلم : "لو قلت نعم لوجبت، ولما استطعتم" ثم قال: "ذروني ما تركتكم، فإنما هلك من كان قبلكم بكثرة سؤالهم، واختلافهم على أنبيائهم، فإذا أمرتكم بشيء فأتوا منه ما استطعتم، وإذا نهيتكم عن شيء فدعوه". ((رواه مسلم)).