extinguish the slain person’s right merely through repentance; like all other human claims, neither retribution (qiṣāṣ) nor pardon fully expiates the killer’s sin. They remove what is between him and Allah, but the right of the murdered person still remains.
Ibn al-Qayyim said: “A homicide entails three distinct rights:

1. The right of Allah, and that is waived by sincere repentance.
2. The right of the heir of the slain, and that lapses through retaliation, settlement, or pardon.
3. The right of the victim himself—Allah will compensate him for his established right and will reconcile him to his killer if the latter repents.”
   9 – Many scholars have argued from this hadith that the one who abandons the prayer is not to be executed for doing so, because he is not included among these three categories. Ibn al-Qayyim, however, maintained: “This very hadith is evidence for killing the one who neglects the prayer, for he has forsaken his religion.”
   10 – The Prophet’s words, “he testifies that there is no god but Allah and that I am the Messenger of Allah,” prove that a person’s Islam is not valid unless he utters the two testimonies—or words conveying their meaning—and that a mere inward acknowledgement does not suffice when he is able to pronounce them. If someone says, “I am a Muslim,” yet does not articulate the two testimonies, he is not judged a Muslim.
   Al-Rawd and other works state: “The repentance of every unbeliever takes the form of embracing Islam by testifying that there is no god but Allah and that Muhammad is the Messenger of Allah.”
   11 – The hadith also shows that once a person has pronounced the two testimonies, he is not interrogated further about the truth of his declaration; he is simply allowed to go free.
   Ibn al-Qayyim said: “He is not required to preface his words with ‘I bear witness.’ Even if he merely says, ‘There is no god but Allah; Muhammad is the Messenger of Allah,’ he is, by consensus, deemed a Muslim and gains the protection Islam affords.”
   12 – As for the one whose disbelief consists in denying an obligatory duty—such as the five daily prayers or zakat—or in declaring lawful what Allah has prohibited, like fornication and wine, or in declaring unlawful what the Muslim community has unanimously agreed