Allah said,

﴿وَلَهُ أَخٌ أَوْ أُخْتٌ﴾

(But has left a brother or a sister), meaning, from his mother's side, as some of the Salaf stated, including Sa`d bin Abi Waqqas. Qatadah reported that this is the view of Abu Bakr As-Siddiq.

﴿فَلِكُلِّ وَحِدٍ مِّنْهُمَا السُّدُسُ فَإِن كَانُواْ أَكْثَرَ مِن ذلِكَ فَهُمْ شُرَكَآءُ فِى الثُّلُثِ﴾

(Each one of the two gets a sixth; but if more than two, they share in a third.) There is a difference between the half brothers from the mother's side and the rest of the heirs. First, they get a share in the inheritance on account of their mother. Second, the males and females among them get the same share. Third, they only have a share in the inheritance when the deceased's estate is inherited in Kalalah, for they do not have a share if the deceased has a surviving father, grandfather, child or grandchild. Fourth, they do not have more than a third, no matter how numerous they were. aAllah's statement,

﴿مِن بَعْدِ وَصِيَّةٍ يُوصَى بِهَآ أَوْ دَيْنٍ غَيْرَ مُضَآرٍّ﴾

(After payment of legacies he (or she) may have bequeathed or debts, so that no loss is caused (to anyone).) means, let the will and testament be fair and free of any type of harm, without depriving some rightful heirs from all, or part of their share, or adding to the fixed portion that Allah or dained for some heirs. Indeed, whoever does this, will have disputed with Allah concerning His decision and division. An authentic Hadith states,

«إِنَّ اللهَ قَدْ أَعْطَى كُلَّ ذِي حَقَ حَقَّهُ فَلَا وَصِيَّةَ لِوَارِث»

(Allah has given each his fixed due right. Therefore, there is no will for a rightful inheritor.)

﴿تِلْكَ حُدُودُ اللَّهِ وَمَن يُطِعِ اللَّهَ وَرَسُولَهُ يُدْخِلْهُ جَنَّـتٍ تَجْرِى مِن تَحْتِهَا الاٌّنْهَـرُ خَـلِدِينَ فِيهَا وَذلِكَ الْفَوْزُ الْعَظِيمُ - وَمَن يَعْصِ اللَّهَ وَرَسُولَهُ وَيَتَعَدَّ حُدُودَهُ يُدْخِلْهُ نَاراً خَـلِداً فِيهَا وَلَهُ عَذَابٌ مُّهِينٌ ﴾

(13. These are the limits (set by) Allah, and whosoever obeys Allah and His Messenger, will be admitted to Gardens under which rivers flow (in Paradise), to abide therein, and is the great success.) (14. And whosoever disobeys Allah and His Messenger, and transgresses His (set) limits, He will cast him into the Fire, to abide therein; and he shall suffer a disgraceful torment.)