The answer to this is based upon an important Islamic principle stating that Allah likes deeds more than knowledge without action. A Muslim is to acquire knowledge but only to the extent of his capabilities and to the extent he is able to act upon.
From the above, it can be concluded that there is a difference between questions that Allah dislikes and between those he commanded Muslims to ask from the people of knowledge [Ahlu al-Dhikr).
They are those questions which entail an exaggerated investigation into a matter, those which bring about strictness either for oneself or for others and which a person does not need on his way to Allah Almighty.
Evidence from the Qur'an
Allah Almighty says,
O you who have believed! Do not ask about things which, if they are shown to you, will distress you [Qur'an 5: 101].
Evidence from Sunna
The Prophet (peace and blessings be upon him and his family) prohibited Muslims from persistent questioning and engaging in debates; he clarified that if Allah Almighty kept silent about a matter, it is by way of facilitation for the people and out of His mercy towards the community [Ummah]. He said: "Truly Allah, Exalted be He, has prescribed certain obligations upon you, so do not neglect them; He has prohibited certain matters, so do not violate them; He prescribed certain limits, so do not transgress them; and He kept silent about certain matters out of mercy, not forgetfulness, so do not delve into them" [Reported by al-Darqatni and others through Abu Tha'laba al-Khushni (may Allah be pleased with him). Ibn al-Salah declared it authentic and Imam al-Nawawi declared it fair).
An example of this is when Allah legislates a certain matter, leaving it open, while it can be executed in more than one manner; a Muslim is to take it in its general sense without asking any questions. It is impermissible to restrict what Allah and His Messenger (peace and blessings be upon him and his family) have left unrestricted without the existence of evidence; otherwise it will be a Bid'a [innovation).
In his commentary on al-Arba'in al-Nawawya, the great scholar al-Taftazani said, "Do not delve into these matters or ask about matters on which Allah kept silent. This is because asking about such matters leads them to become obligations that may be hard to observe. Rather, a person must assume the principle of the presumption of permissibility."
The Prophet (peace and blessings be upon him and his family) illustrated the heinous sin that Muslims commit due to their persistent questions and investigations. Amir ibn Sa'd narrated through his father (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said, “Truly, the gravest sinner amongst Muslims is he who asks about something and probes into it and it becomes prohibited due to his insistent questions” [Muslim).
Abu Huraira (may Allah be pleased with him) narrated that the Prophet (peace and blessings be upon him and his family) gave a sermon and said, "O people! Allah has commanded you to perform Hajj, so perform it." Upon this a man asked: "O Messenger of Allah! Should we perform it every year?" The Prophet did not reply. The man repeated his question three times. Thereupon, the Messenger of Allah (peace and blessings be upon him and his family) said: "If I say yes, it will become obligatory and you will not be able to perform it." Then he said, "Do not ask me about things on which I remain silent. Those who came before you were ruined due to their incessant questions and controversy with their Prophets. When I order you to do something, do it to the best of your abilities and when I forbid you from doing something, leave it" [Bukhari and Muslim].
In his commentary on the above hadith, the great scholar al-Manawi wrote in his book Fayd al-Qadir Sharh al-Jami' al-Saghir 3/562, "It means that the Prophet ordered people not to be persistent in asking about the matters he did not mention in religion as long as he remains silent. This is because their probing may result in certain obligations or restrictions. The Prophet ordered people to take the apparent meaning of his orders and not delve into matters as the people of the Book used to do. He also prohibited them from asking about matters which have been made clear even if they can be executed through different manners, as this may lead to different answers as was the case with the people of Israel who asked incessant questions which led to Allah imposing hardships upon them. The Prophet (peace and blessings be upon him and his family) feared that the same hardships befall his community."
- Questions about the legal rulings of matters that benefit a Muslim in regards to his action and behavior and which guide him to the right path and bless his deeds.
- Questions a student asks his teacher.