Observations on Islamic Law of Inheritance

The BASIS of Islamic Law : 

The word "Shariah" means "The Path". In general Shariah includes the followings : 

1) Instructions from Allah, the Quran 

2) Prophet Muhammad directed Way of Life, the Hadith 

Historically there are 2 facts to consider that : 

1) Quranic verses came to Prophet Muhammad gradually over a period of approximately 23 years, beginning on 22 December 609 CE, when Muhammad was 40, and concluding in 632, the year of his death.

2) Muhammad never Published the Quran while he lived. It was first put-together & published around 632 while one of Muhammad's companion Omar ( later the 2nd Khaliph) decided to collect all fragments, contents from many kind of media. Later after 644 Usman   merge many variations/versions of Quran into just-one. 

Here is a reference from another website 

"Not long after the Prophet's death (632), his successor Abu Bakr, the first Caliph of Islam, asked Muhammad's former head scribe, Zaid Ibn Thâbit, to make a copy. this he did. On Omar's initiative (the future second Caliph), Zaid consulted all the information he could assemble at Madina: the witness of the Hafizun, copies of the Book written on various materials belonging to private individuals, all with the object of avoiding possible errors in transcription. Thus an extremely faithful copy of the Book was obtained."  

URL http://www.islam-guide.com/bqs/15authenticity.htm

3)  The Hadiths were again never written while prophet Muhammad lived. It was later collected and versioned by few. 

The Messenger 

Ref:

Islamic Laws of Inheritance by Dr. Abid Hussainhttp://www.islam101.com/sociology/inheritance.htm