Hafsah was the daughter of Umar ibn Al-Khattab and Zaynab bint Mazoon and sister of the great sahabi (Companion of the Prophet) Abdullah ibn Umar. She was born in Makkah around 3 years before the Revelation and was around the age of 8 when her father accepted Islam.
She married Khunays ibn Khadaqa who was one of the Muslims that had both immigrated to Abyssinia and Medina for the sake of Allah. He witnessed the Battle of Badr and was severely wounded in the Battle of Uhud. He passed away as a shahid (martyr) several days later and Hafsah was left as a widow.
The marriage took place 3 AH in the month of Sha'aban. Sawdah bint Zama'ah was pleased with Hafsah's marriage to the Prophet (PBUH) while Aisha who had only recently married the Prophet (PBUH) remained jealous of Hafsah when she recalled Hafsah's youth and noble lineage. However, after the Prophet married others, she and Aisha were the closest.
"She is an often fasting and worshipping lady and she will be your wife in Paradise too."