A man from the Ansar accepted Islam, then turned back and joined those who committed shirk. Later he felt remorse, so he sent word to his people, "Ask the Messenger of Allah ﷺ for me whether there is any way for me to repent."So his people came to the Messenger of Allah ﷺ and said, "So-and-so has become remorseful, and he asked us to inquire of you whether there is any repentance available to him."Then this was revealed, "How shall Allah guide a people who disbelieved after their belief" up to His words, "Forgiving and Merciful" [Al Imran 3:86–89].So he sent word to the man, and he accepted Islam.
كان رجل من الأنصار أسلم، ثم ارتد، ولحق بالشرك، ثم تندم، فأرسل إلى قومه: سلوا لي رسول الله ﷺ هل لي من توبة؟ فجاء قومه إلى رسول الله ﷺ فقالوا: إن فلانا قد ندم وأنه أمرنا أن نسألك: هل له من توبة؟ فنزلت: {كيف يهدى الله قوما كفروا بعد إيمنهم} إلى قوله {غفور رحيم} [آل عمران: ٨٦-٨٩]. فأرسل إليه فأسلم.
Nasai (4068) and Hakim (4/366) both narrated it through the route of Dawud, who is Ibn Abu Hind, from Ikrima, from Ibn Abbas, mentioning it. Hakim said, its chain is sahih. Abdul-Razzaq said in his tafsir (1/131), Jafar bin Sulayman told us, Humayd Araj narrated to us, from Mujahid, who said, Harith bin Suwayd came and embraced Islam with the Prophet ﷺ, then Harith disbelieved and returned to his people. So Allah revealed, "How shall Allah guide a people who disbelieved after their belief" [Al Imran 3:86], up to His saying, "except those who repent after that and reform themselves, for indeed Allah is forgiving and merciful" [Al Imran 3:89]. He said, a man from his people carried it to him and recited it to him. Harith said, "By Allah, I have known you to be truthful, and the Messenger of Allah ﷺ is the most truthful of the three." He said, so Harith returned and embraced Islam, and his Islam became good. Its chain is disconnected.Malik narrated in the Chapter on Judgments (18) from Abdul-Rahman bin Muhammad bin Abdullah bin Abdul-Qari, from his father, that he said, a man came to Umar bin Khattab from the side of Abu Musa Ashari, and he asked him about the people, so he informed him. Then Umar said to him, "Was there any news from far-off lands among you?" He said, "Yes, a man disbelieved after his Islam." He said, "What did you do with him?" He said, "We brought him near and struck his neck." Umar said, "Why did you not imprison him for three days, feeding him a loaf of bread each day, and asked him to repent, so that perhaps he would repent and return to Allah's command?" Then Umar said, "O Allah, I was not present, nor did I command it, nor was I pleased when it reached me."Shafii narrated it from Malik, and Bayhaqi (8/206) narrated it from him. Shafii said, "Whoever has not looked into it carefully claims that what was narrated from Umar is not established, because he does not know it to be connected." Ibn Turkmani followed up on this, saying, "Abdul-Razzaq narrated this report from Mamar, and Ibn Abu Shayba narrated it from Ibn Uyayna, both of them from Muhammad bin Abdul-Rahman bin Abdul-Qari, from his father. According to this, it is connected, because Abdul-Rahman bin Abd heard from Umar."I say, Abdullah bin Abd, without any addition, Al-Qari, with the doubling of the ya, and Abdul-Rahman bin Abd, both of them have a sighting, and it has been said that they have companionship. His saying, "news from far-off lands," means, was there any new news that came from distant countries?It is derived from the verse, the hadith, and the reports that an apostate is asked to repent, and this is the view of the majority of the people of knowledge, Abu Hanifa, Malik, Shafii, and Ahmad. Ata bin Abu Rabah, Ibrahim Nakhai, Uzai, Sufyan Thawri, and others held this view as well. They interpreted the saying of the Prophet ﷺ, "Whoever changes his religion, kill him," to mean, if he does not return to the truth after being asked to repent, and that he is not killed immediately. There are other views on this matter mentioned by Ibn Munzir in Al-Awsat (13/460), but what is sahih is what the majority of the people of knowledge held.