First of all you have to know that if a person does not understand Arabic, he cannot understand the word of Allaah (Qura'an) or the Ahadeeths of the our beloved Prophet Muhammed (sallallahu alayhi wasallam). Even if he knows very little then he would still be in doubt since Arabic is a language that has many meanings to one general term.
Arabic is a vast language and is the tongue of the Arabs. (speech of the Arabs).
Imam Shafee (rahimahullah) said in al-umm :
"Among the knowledge of the Book of Allah is knowing that all of the Book was only sent BY THE VAST TONGUE OF THE ARABS."
Imam Shafee also said:
"...and I have only started with what I have described of the Qura'an been revealed in the Arab tongue none other: because NO ONE KNOWS THE CLARIFICATION OF THE KNOWLEDGE OF THE BOOK WHEN HE IS IGNORANT OF THE VAST TONGUE OF THE ARABS, AND ITS MANY SIDES, ITS GENERAL AND DIFFERENT MEANINGS. AND THE ONE WHO KNEW IT HE WILL BE FREE FROM THE DOUBTS, WHO THE ONE IGNORANT FELL IN."
So what is the answer to the question above??
The answer is that a person MUST study the Arabic language for 2 reasons :
1. To understand the Qura'an and Sunnah;
2. So that they do not fall into the errors of speech.
HOW DID THE PEOPLE FALL INTO ERRORS OF SPEECH ?
During the time of Ali (radallaahu anhu) many people from all around Arabia came into the fold of Islaam. The speech of Arabic in different ways spoilt the ARABIC LANGUAGE.
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