The previous narration.
Imam al-Shafi'i (may Allah have mercy on him) said: Those hypocrites whose Islam is outwardly manifest, it has been forbidden to kill them. The Shaykh said: Regarding the story narrated by Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him), that when the Prophet (peace and blessings be upon him) was distributing wealth a man said: "Fear Allah (in this distribution)," Sayyiduna Khalid bin al-Walid (may Allah be pleased with him) asked permission (saying): Shall I kill him? He (peace and blessings be upon him) said: "No, perhaps he prays." Khalid said: "How many a person who prays says with his tongue what is not in his heart!" And the Prophet (peace and blessings be upon him) said: "I have not been commanded to search into people's hearts or to cut open their bellies."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المرتد / 16826