Tafsir of Al-Isra 17:33

{Except by right} Meaning: Except for one of three reasons: that they apostatize, or intentionally kill a believer, or commit adultery after having been married.

{Wronged} Meaning: One who has not committed any of these three acts.

{To his guardian} The one who shares a kinship with him that necessitates seeking retribution for his blood. If he has no guardian, then the Sultan is his guardian.

{Authority} Meaning: Power over the killer to exact retribution, or a proof by which he may prevail over him.

{So let him not exceed} The pronoun refers to the guardian. It means: let him not kill anyone other than the killer, nor kill two people for one killer, as was the custom of the Pre-Islamic era (Jahiliyyah). When one of them was killed, they would kill a group in retaliation, to the point that Muhalhil said when Bujayr ibn al-Harith ibn 'Abbad was killed: "Take a sandal strap for Kulayb." And he said: Every person killed for Kulayb is a deception, Until the killing reaches the family of Murra. They used to kill someone other than the killer if there was no equal match. It is also said that "excess" refers to mutilation.

Abu Muslim, the statesman, read it as fala yusrifu (in the nominative case), as a declarative statement in the sense of a command, which carries an emphasis not present in the imperative. According to Mujahid, the pronoun refers to the first killer. It is also read as fala tusrif (addressing the guardian or the killer of the wronged). In Ubayy’s reading, it is fala tusrifu (plural), referring back to "Do not kill."

{Indeed, he was supported} The pronoun refers to:

1. The guardian: Meaning, it is sufficient for him that Allah has supported him by mandating retribution, so he should not seek more than that; and that Allah has supported him through the aid of the Sultan and by enabling the believers to exact justice, so he should not transgress beyond his right.
2. The wronged person: Because Allah is his supporter, having mandated retribution for his killing, and He will support him in the Hereafter with reward.
3. The one whom the guardian kills unjustly: If the guardian exceeds the limit in killing him, then that person is supported by the mandate of retribution against the one who exceeded the limit.

{And do not approach the orphan's wealth except in the way that is best until he reaches maturity. And fulfill the covenant; indeed, the covenant will be questioned.}