Al-Awza'i (may Allah have mercy on him) said: Mu'awiyah bin al-Hakam (may Allah be pleased with him) accepted Islam in the last period of the Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) did not order him to repeat the prayer. Whoever speaks in prayer out of forgetfulness or ignorance, his prayer is still valid, and whoever speaks deliberately must start the prayer afresh. Imam al-Shafi'i (may Allah have mercy on him) indicated most of what we have related from others in the book Ikhtilaf al-Hadith, and what has been narrated to us from others on this matter supports his view.
Imam al-Shafi'i (may Allah have mercy on him) said: Someone says: Is the Dhul-Yadayn from whom you narrate not the one who was martyred at Badr? I say: No! Imran (may Allah be pleased with him) named him al-Khirbaq and said: short-handed or long-handed, whereas the one martyred at Badr was Dhul-Shimalayn (may Allah be pleased with him).
Imam al-Bayhaqi (may Allah have mercy on him) said: The one who was martyred at Badr was Dhul-Shimalayn bin Abd Amr bin Nadlah (may Allah be pleased with him), from Khuza'ah, an ally of Banu Zuhrah. Urwah bin al-Zubayr (may Allah have mercy on him) also mentioned it in this way.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3926