Narrated `Abdullah bin `Umar: One of the evil deeds with bad consequence from which there is no escape for the one who is involved in it is to kill someone unlawfully.
Explanation & Benefits
Shaykh Abdul Sattar al-Hammad
Hadith Commentary:
In this hadith, the gravity of unlawful killing is described, indicating that if someone becomes involved in such a matter, it is extremely difficult to escape from it.
In one narration, it is mentioned that Ibn Umar (radi Allahu anhuma) said:
Whoever commits unlawful killing will depart from this world carrying cold water with him, for he will not enter Paradise. Furthermore, the Prophetic statement is: "In the sight of Allah, the unlawful killing of a believer is greater than the destruction of the entire world." (Jami‘ at-Tirmidhi, Al-Diyat, Hadith: 1395)
Ibn al-‘Arabi (rahimahullah) states that to kill an animal without reason is a grave crime, so how much greater is the crime if the one killed without reason is a human being—and that too a Muslim, and moreover, one who fears Allah and is extremely pious. (Fath al-Bari: 12/234)
Source: Hidayat al-Qari: Commentary on Sahih Bukhari, Urdu, Page: 6863