Ibn Majah

Commentary:
(1)
From the perspective of its chain of narration, this narration is weak; however, the importance and necessity of knowledge of the Qur’an and Hadith is established by many other evidences.
Similarly, the importance of the knowledge of inheritance (mirath) is also self-evident and needs no further clarification.

(2)
By “decisive verse” (muhkam ayah) is meant a verse that is neither abrogated nor ambiguous (mutashabih).
The knowledge of abrogating and abrogated (nasikh and mansukh) in the Qur’an and Hadith is also of great importance; without it, one may err in making decisions regarding any issue.

(3)
By “established Sunnah” is meant that the Sunnah is authentically proven (with a sahih chain) from the Messenger of Allah (sallallahu alayhi wa sallam) and is not abrogated.

(4)
By “justice in financial rights” is meant that in financial matters, taking or giving anything without legal (shar‘i) entitlement is injustice, and this leads to corruption spreading in the world. Therefore, it is necessary for a Muslim to acquire obligatory knowledge regarding these matters, and among them is the knowledge of inheritance (mirath).

Benefits and Issues:
➊ This narration is weak in its chain of transmission.
For a detailed discussion, see: (Irwa’ al-Ghalil: 1664)

➋ The verses of the Noble Qur’an are of two types: (1) Muhkam (clear and decisive), (2) Mutashabihat (ambiguous).
As it is mentioned in the Noble Qur’an: {هُوَ الَّذِي أَنْزَلَ عَلَيْكَ الْكِتَابَ مِنْهُ آيَاتٌ مُحْكَمَاتٌ هُنَّ أُمُّ الْكِتَابِ وَأُخَرُ مُتَشَابِهَاتٌ } [آل عمران: 7] “He (Allah) is the One Who has sent down to you the Book; in it are verses that are muhkam (clear and decisive)—they are the foundation of the Book—and others are mutashabihat (ambiguous).”
...
(Muhkam) refers to those verses in which commands, prohibitions, rulings and issues, and stories and narratives are mentioned; their meaning and interpretation are clear and definite.
And the second type (mutashabihat) refers to those verses that pertain to metaphysical matters, such as the essence of Allah, divine decree and predestination, Paradise and Hell, and the angels, etc., which human intellect is incapable of fully comprehending, and in which there is room for interpretation or at least such ambiguity that it is possible for the common people to be led astray by them.
Therefore, the people of innovation, whose hearts are diseased, or the people of falsehood, persistently pursue the mutashabihat verses and, through them, cause “fitnah” (trials and tribulations).
(Summarized from Tafsir Ahsan al-Bayan)

➌ The authenticity and strength of the chain of transmission is the basis for the proof of hadiths and Sunnah.
Such narrations whose chain is unreliable cannot in any way be accepted as the statement of the Messenger of Allah (sallallahu alayhi wa sallam).

➍ In financial matters, taking or giving anything without legitimate Islamic entitlement is oppression, and this leads to corruption spreading in the world. Therefore, it is necessary for a Muslim to acquire knowledge of these matters.
And among these is the knowledge of inheritance (ilm al-mirath).
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Hadith Authentication:
Its chain of narration is weak.
In this narration, both Abdur Rahman bin Ziyad bin An'um al-Ifriqi and his teacher Abdur Rahman bin Rafi' al-Tanukhi are weak. See: [تقريب التهذيب 3862، 3856] and the books of biographical evaluation (kutub asma' al-rijal).

Note:
By "muhkam verse" is meant a verse whose meaning is clear and explicit, with no room for interpretation (ta'wil). By "established Sunnah" (sunnat qaimah) is meant a Sunnah that is established, continuous, and proven.
◄ By "just obligation" (faridah 'adilah) is meant an obligation characterized by justice and fairness, in which there is only good for the people.
◄ This brief linguistic explanation has been provided as a benefit and for understanding; otherwise, there is no need for jurisprudential analysis (fiqh al-hadith) of a weak narration.