Sahih Bukhari Volume 5, Book 59, Hadith Number 328.

Narrated By Mu’adh bin Rifa’a bin Rafi: Rifa’a was one of the warriors of Badr while (his father) Rafi’ was one of the people of Al-‘Aqaba (i.e. those who gave the pledge of allegiance at Al-‘Aqaba). Rafi’ used to say to his son, “I would not have been happier if I had taken part in the Badr battle instead of taking part in the ‘Aqaba pledge.”