Is the ijtihad of the Companions regarded as a religious evidence?

Dear Brother / Sister,

The ijtihad of the Companions on an issue is regarded as a religious evidence. Every Companion is a mujtahid.

Since the Companions knew Arabic well and they understood the purpose of Allah and His Messenger (pbuh) due to being together with the Prophet (pbuh), there are a lot of mujtahids among the Companions. However, the number of mujtahids among the Companions from whom decrees and fatwas were reported is about one hundred and thirty. The Companions called Fuqaha as-Sab'a (the seven fiqh scholars) are as follows: Hz. Umar, Ali, Aisha, Zayd b. Thabit, Abdullah b. Mas'ud, Abdullah b. Abbas and Abdullah b. Umar (Ibnul-Qayyim, I'lamul-Muwaqqiin, thq. M. Muhyiddin Abdulhamid, Egypt 1955, I, 14 ff)

When the Companions could not find a verse in the Quran, they referred to the Sunnah and deduced the necessary decree from it. The caliph would ask his friends about the issue that was in question; anyone who knew a hadith about the issue would present it and the issue would be settled.  

For instance, once, a maternal grandmother went to Hz. Abu Bakr and asked her share from the inheritance of the son of her daughter, who was dead. Hz. Abu Bakr said he did not know any Quranic verse about the issue. Then, he turned toward the Companions and asked, "Does any of you know a decree about the issue given by the Prophet (pbuh)?" Mughira b. Shu’ba, "I remember that the Prophet (pbuh) gave a share of one-sixth of the inheritance to the grandmother." Hz. Abu Bakr said, "Does anybody else know about it?" When another Companion witnessed about it, the maternal grandmother was given the right of one-sixth of the inheritance. Then, during the caliphate of Hz. Umar, the paternal grandmother came and asked for her share. Hz. Umar said, «I do not know that a separate share is given to you in the Quran; this one-sixth belongs to both of you.»

When the Companions could not find a nass in the Book and the Sunnah, they would make ijtihad. This was a method accepted by the Prophet (pbuh). When the Prophet sent Muadh b. Jabal to Yemen as the judge, the Prophet (pbuh) asked him, «What will you decree with?» He said, «With the book of Allah.» The Prophet (pbuh) asked, «What if you cannot find in the Book?» He said, <<With the Sunnah of the Prophet (pbuh).» «What if you cannot find in it?» Muadh said, «I will make ijtihad based on my view.» Thereupon, the Prophet (pbuh) said, «Praise be to Allah, who made the messenger of the Prophet successful in a way that would please Him!»

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