How can claimants be convinced that the law of inheritance in the Qur’an is complete and without contradiction, even though some inheritance cases (such as: a man dies and leaves behind three daughters, a wife, and two parents) compel us to enter into the issue of Al-Aoul (the increase in the shares of the heirs beyond the total inheritance)?

The Holy Quran is complete and has no contradictions. It is the primary source of legislation, but it did not detail every issue. The Quran stipulated that the Sunnah is a source of legislation, as in His (Allah's) saying: "And whatever the Messenger gives you, take it." The Prophet (peace be upon him) added the Sunnah of the Rightly Guided Caliphs and Ijma' (consensus) as sources of legislation. The issue of 'awl (pro rata reduction of shares in inheritance) occurred during the time of 'Umar ibn al-Khattab and 'Ali ibn Abi Talib (may Allah be pleased with them), whereby the inheritance is divided among the heirs according to their shares when needed, as indicated by Al-'Abbas ibn 'Abd al-Muttalib (may Allah be pleased with him). Ibn Qudamah mentioned that no disagreement is known regarding the issue of 'awl, and it is among the merits of Islam due to its justice and its ability to address new developments.