This question has much speech regarding it and perhaps its complete answer is [already] found in some [other] tapes. However, there is no harm in answering it [again]: is it allowed to explain the Quran relying upon the [Arabic] language [alone] without returning to the Sunnah? This is the question.
“It is necessary for the one who wants to explain the Quran to have knowledge of Arabic language first because the Quran, as is well known to everyone, was revealed in clear Arabic language. However, this is not sufficient. If the most Arab of Arabs came and wanted to explain the Quran in his language which the Quran was revealed, he will not be able to be proficient in his tafseer of the Quran which was revealed in that [language]. This is because there is a custom with Scholars of [there being] two languages: the customary language which the Quran was revealed and the language of the Legislation
That is that Allah, the Exalted made new [meanings], sometimes in wordings well-known to the Arabs like Hajj and Zakat. Hajj means purpose in the language and Zakat linguistically means purification. However, the Legislator made the word Hajj to mean worship such that if one of its pillars is missing it will not be a completed. Likewise, Zakat and prayer. For prayer means supplication in the language.
إن الله وملائكته يصلون على النبي
Allah sends His Salat (Graces, Honours, Blessings, Mercy, etc.) on the Prophet (Muhammad) and also His angels too (ask Allah to bless and forgive him). O you who believe! Send your Salat on (ask Allah to bless) him (Muhammad), and (you should) greet (salute) him with the Islamic way of greeting (salutation i.e. AsSalamu ‘Alaikum)
However, prayer when it is uttered only means the act of worship which has conditions, pillars, etc.
So it is not possible for anyone, however knowledgeable he is of the Arabic language, to explain the Quran correctly except by relying upon the language of the Legislation. The language of the Legislation is taken from the two sources: the Book of Allah and the Sunnah of the Messenger of Allah (ﷺ). The explanation of this has come the statement of Exalted:
وأنزلنا إليك الذكر لتبين للناس ما نزل إليهم
And We have also sent down unto you (O Muhammad) the reminder and the advice (the Quran), that you may explain clearly to men what is sent down to them
So this verse includes two affairs. One is that which is clarified and the other is the one who clarifies it. What is clarified is what was revealed to the Messenger of Allah (ﷺ) in terms of the Speech of Allah and it is the Noble Quran. As for the one who clarifies, then it is the Messenger of Allah. So like that, his Sunnah divides into three types: his statements, actions or approvals. The one who does not know his (ﷺ) statements, actions, and what he (ﷺ) approved from that which he saw occur between the people, then such a person can never explain the Quran and instead will make very grave mistakes. There even occurred some examples in the time of the Prophet (ﷺ) when the statement of the Exalted:
ولم يلبسوا إيمانهم بظلم أولئك لهم الأمن وأولئك هم المهتدون
It is those who believe (in the Oneness of Allah and worship none but Him Alone) and confuse not their belief with Zulm (wrong i.e. by worshipping others besides Allah), for them (only) there is security and they are the guided
Became confusing to the Companions (may Allah be pleased with them). They said: O Messenger of Allah (ﷺ), who from us does not confuse his Iman with oppression? That was because they understood oppression here to be general and in reality there is no one after the Prophets who is infallible from falling into the likes of this general oppression. So like this, they feared that this verse included them in that of they were from those who do not have security because they confuse their iman with oppression. The Prophet (ﷺ) said to them that the affair is not like what you say. Did you know not recite the statement of Allah, the Exalted:
وإذ قال لقمان لابنه وهو يعظه يا بني لا تشرك بالله إن الشرك لظلم عظيم
And (remember) when Luqman said to his son when he was advising him: “O my son! Join not in worship others with Allah. Verily! Joining others in worship with Allah is a great Zulm (wrong) indeed
[Reported by Bukhari (no. 3428) and Muslim (no. 124)]
So the oppression mentioned in the first verse is the oppression mentioned in the second verse. If the Companions of the Messenger (ﷺ) were confused about the interpretation of oppression in the first verse, then those who come after them will be confused in what is less than this. It is necessary for the one explaining the Quran to be well-versed in the Sunnah, to the best of his ability, in the three types: his (ﷺ) statements, his actions, and his approvals”.
[Silsilatul-Huda wan-Nur no. 1071]
Faisal Ibn Abdul Qaadir Ibn Hassan