Lady Aisha Siddiqa (may Allah be pleased with her) narrates: The Prophet Muhammad (peace and blessings be upon him) recited the statement of Allah Almighty: "He it is Who has sent down to you the Book; in it are verses that are clear."
He recited this verse till the end, then said: "When you see those who recite the ambiguous verses, then know that these are the people Allah has referred to, so beware of them."

Sayyiduna Abu Hurairah, may Allah be pleased with him, narrates this statement of the Prophet Muhammad, peace and blessings be upon him: "The Qur'an has been revealed to me in seven modes." To argue about the Qur'an is disbelief.
(He said this three times, then said:) "Whatever of it you understand, act upon it, and whatever you do not have knowledge of, refer it to one who knows."
(Imam Ibn Hibban, may Allah have mercy on him, says:) The statement of the Prophet, peace and blessings be upon him: "Whatever of it you understand, act upon it," contains a hidden mention of ability. His intention is: regarding the Book, whatever ruling you recognize, act upon it according to your ability.
The words of the narration: "And whatever you do not have knowledge of, refer it to one who knows," contain a prohibition against violating this command, and that command is: people should not ask questions about religious matters from someone who does not possess knowledge.