He came to the Messenger of Allah ﷺ regarding the ransom of Badr. Ibn Jafar said, "regarding the ransom of the polytheists." He had not yet embraced Islam at that time.He said, "I entered the mosque while the Messenger of Allah ﷺ was praying Maghrib, and he was reciting Surah at-Tur. It was as though my heart split open when I heard the Quran."Ibn Jafar's wording was, "It was as though my heart split open when I heard the Quran."
قال حدثنا عفان ومحمد بن جعفر قالا حدثنا شعبة عن سعد بن إبراهيم قال سمعت بعض إخوتي عن أبي
أنه أتى رسول الله ﷺ في فداء بدر قال ابن جعفر في فداء المشركين وما أسلم يومئذ فدخلت المسجد ورسول الله ﷺ يصلي المغرب فقرأ بالطور فكأنما صدع عن قلبي حين سمعت القرآن قال ابن جعفر فكأنما صدع قلبي حيث سمعت القرآن
Its chain of transmission is sahih, even though it may appear disconnected at first glance. It is not actually disconnected, because Saad's brothers are all trustworthy. In any case, the hadith has already appeared at 16629.