Bukhari

Hadith Commentary:
The word "shaqita" is transmitted in both forms, i.e., in the present tense and in the first person. The meaning of the former is: if I myself am not just, then you are wretched, because you are my follower.
When the guide and the one followed is not just, then what hope is there for the disciple? And this hadith will be mentioned in full detail later.
The relevance to the chapter is that the Messenger of Allah (sallallahu alayhi wa sallam) may have given someone more or less from the khums according to his own judgment, when Dhu al-Khuwaysirah raised this objection, because the remaining four shares are distributed equally among all the fighters in the cause of Allah.
However, his objection was incorrect, as he harbored such a suspicion regarding the Messenger of Allah (sallallahu alayhi wa sallam).
Whereas, no one more just and fair than the Messenger of Allah (sallallahu alayhi wa sallam) has ever been born among mankind, nor will there ever be.

Hadith Commentary:
➊
Another meaning of the last part of the hadith has also been stated: that the Messenger of Allah (sallallahu alayhi wa sallam) said,
“O wretched one! If I do not act justly, then who will act justly?”
Imam Nawawi (rahimahullah) has considered this meaning to be the preferred one.
(Fath al-Bari: 6/291)
Since the Messenger of Allah (sallallahu alayhi wa sallam) had the authority to distribute the wealth of khums at his own discretion, and he may have given more to someone due to their distinguished services, it was for this reason that the objector accused the Messenger of Allah (sallallahu alayhi wa sallam) of injustice, which was not based on reality.

➋
In any case, the position of Imam Bukhari (rahimahullah) is that the Messenger of Allah (sallallahu alayhi wa sallam) and the rulers who came after him have discretionary authority over the spoils of war (ghanimah), fay’, jizyah, and the wealth of khums, etc.
They may give to whomever they wish and withhold from whomever they wish.
And Allah knows best.

Commentary:
(1)
The person who committed this insolence was named Dhul-Khuwaysirah.
And this incident occurred after the Battle of Hunayn,
when the Prophet sallallahu alayhi wa sallam distributed the spoils of war obtained from the Battle of Hunayn among the warriors at the place of Ji‘ranah.

(2)
To object to any action or statement of the Prophet sallallahu alayhi wa sallam, or to declare it incorrect, or to consider any of his sallallahu alayhi wa sallam’s commands as impracticable, is the practice of the hypocrites; such an act cannot possibly be committed by a believer.

(3)
In this incident, there is a lofty example of the forbearance, forgiveness, and patience of the Prophet sallallahu alayhi wa sallam, that despite such insolence, he sallallahu alayhi wa sallam did not punish him.

(4)
When Umar radi Allahu anhu, having declared this person a hypocrite, sought permission to kill him, the Prophet sallallahu alayhi wa sallam did not refute him.
It is as if he sallallahu alayhi wa sallam confirmed the person’s hypocrisy, yet, on account of wisdom, refrained from giving him the death penalty.

(5)
In this person’s action, there is a denial of the authority of the Prophetic statement. Later, the Khawarij also rejected many ahadith because, in their view, they were contrary to the supposed meaning of the Qur’an which, according to them, was the correct meaning of the Qur’an.
But in the view of Ahl al-Sunnah, the correct meaning of the verses of the Noble Qur’an is that which is supported by authentic ahadith.

Benefit:
The Messenger of Allah sallallahu alayhi wa sallam exercised such perfect justice in every single matter that there is no parallel to it. Yet, some troublemaking hypocrites continued to express doubts and suspicions about the Noble Prophet sallallahu alayhi wa sallam, because in reality, hypocrites are actually disbelievers, but outwardly they wear the cloak of Islam.

By Allah! Even now there are hypocrites who outwardly profess Islam, but in reality, they are agents of the Jews and Christians. Furthermore, in this hadith, there is mention of some of those wretched people who will recite the Qur’an, but will remain far from acting upon the Noble Qur’an. By Allah! Such people still exist today. May Allah Almighty reform the Muslim Ummah, for evils and tribulations have become widespread, and the circumstances for the reformers have been made difficult.