I am looking for a reference to the claim that Torah given to Prophet Musa (a) was the first complete shariah. Could someone refer to any source?
Verily, We did send down the Taurat (Torah) [to Musa (Moses)], therein was guidance and light, by which the Prophets, who submitted themselves to Allah's Will, judged the Jews. And the rabbis and the priests [too judged the Jews by the Taurat (Torah) after those Prophets] for to them was entrusted the protection of Allah's Book, and they were witnesses thereto. Therefore fear not men but fear Me (O Jews) and sell not My Verses for a miserable price. And whosoever does not judge by what Allah has revealed, such are the Kafirun (i.e. disbelievers - of a lesser degree as they do not act on Allah's Laws). (Qur'an 5:44)
The word Tawrat has occurred eighteen times in the Quran and the name of Musa is mentioned 136 times in the Quran.
More can be read from here.
As for the complete Shariah, yeah it can be said so by considering these verses...
(Jews like to) listen to falsehood, to devour anything forbidden. So if they come to you (O Muhammad SAW), either judge between them, or turn away from them. If you turn away from them, they cannot hurt you in the least. And if you judge, judge with justice between them. Verily, Allah loves those who act justly.
But how do they come to you for decision while they have the Taurat (Torah), in which is the (plain) Decision of Allah; yet even after that, they turn away. For they are not (really) believers. (Qur'an 5:42-43)
And about the first complete Shariah, I don't think so. Because there were many prophets before Prophet Musa (pbuh). Anyone before him might have got the complete shariah. It can be said, Torah was one of the complete Shariah given to their prophets. But still, although may be complete, they are to be either abrogated or be completed by the current book Qur'an and the current Shariah system of Islam.
May the creator guide us all.
It is not clear what you mean by complete. A shariah cannot be expected to be incomplete, since it is meant to guide the humans through life on earth. I will try to answer not accentuating on this adjective.
If we understand shariah in a theological sense as a set of rules for a community: Then the Torah was not the first shariah. The first shariah is the shariah for Adam and his followers, because Adam was the first human being.
As mentioned in the other answer, each prophet and messenger came to guide their respective community, either with new shariah or confirming an existing one.
What can be said with confidence is that the shariah of Muhammad is the last one valid until the last day, because of the following reasons:
- Muhammad is the seal of the prophets, sent to all humankind until the last day.
- The Mahdi, according to (reliable) hadith , will rule according to the shariah Muhammad was sent with.
- Jesus will descend during Mahdi's time and he will pray behind the Mahdi saying: each community has its own imam, i.e. the Mahdi remains Khalif and Jesus follows the same shariah as the Mahdi.
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