A person who misappropriates booty is one who conceals something of the spoils he acquired in jihad.
For example, he acquires something along with the other fighters, then conceals it, intending to keep it exclusively for himself. Such a person has committed a grave sin—may Allah protect us—and perpetrated one of the major sins. Allah, Exalted is He, says:
“Whoever misappropriates anything shall bring it forth on the Day of Resurrection.” [Surah Al Imran 3:161]
On the Day of Resurrection, he will come carrying on his neck what he misappropriated, in disgrace, shame, and humiliation.
Because this matter is serious and concerns the Muslim community at large, the Prophet, may Allah’s peace and blessings be upon him, refrained from offering the funeral prayer for one who misappropriated booty, as a deterrent to those who came after him. This does not waive the funeral prayer for the rest of the Muslims; rather, they are obliged to offer it for him.
The evidence for this is what Zayd ibn Khalid, may Allah be pleased with him, narrated: “A man from Juhaynah died on the day of Khaybar, and this was mentioned to the Messenger of Allah, may Allah’s peace and blessings be upon him. He said, ‘Offer the funeral prayer for your companion.’ The people’s faces changed, and when he saw their reaction, he said, ‘Your companion misappropriated something in Allah’s cause.’ We searched his belongings and found among them beads belonging to the Jews, worth less than two dirhams.” (1)
His statement, “Nor for one who killed himself,” means that the imam should not offer the funeral prayer for one who killed himself, as a deterrent to those who remain after him. For one who kills himself—may Allah protect us—has committed one of the major sins, and he will be punished in Hell with that by which he killed himself. If he killed himself with a dagger, then in the Fire of Hell he will have a dagger in his hand with which he will stab himself. If he killed himself with poison, then he will have poison in his mouth, which he will keep drinking in the Fire; and if