Hafsa is the daughter of Hazrat Umar ibn Khattab (R) and one the noble wives of Rasulullah r. Her mother was Zaynub bint Maz'oon (Radiyallahu Anha). Before marrying Rasulullah (Sallallahu Alaihi Wasallam) she was married to Hazrat Khunais ibn Huzafah As Sahmi t. She made Hijrah to Madeenah Munawwarah with him. He was severely wounded in the Battle of Badr and passed away thereafter.
Hazrat Bilal (R) was of African origin and was born from the slaves of the Banu Jumah tribe. He accepted Islam in the early days and was the first person to publicly proclaim his faith in Makkah. He participated in Badr and all the battles that took place therafter. Umayyah ibn Khalaf was one of his chief tormentors when he accepted Islam. Allah Ta'ala made it such that Hazrat Bilal (R) himself killed him in the Battle of Badr.