It was during the pre-Islamic era that Hazrat Zaid (radhiyallahu ‘anhu) was once travelling in a caravan with his mother, who was going to her father’s town, when the caravan was waylaid and looted by the Banu Qais clan. They took Hazrat Zaid (radhiyallahu ‘anhu) as a slave and sold him in Makkah Mukarramah.
Hazrat Hakeem bin Hizaam (radhiyallahu ‘anhu) purchased Hazrat Zaid (radhiyallahu ‘anhu) for his aunt, Hazrat Khadijah (radhiyallahu ‘anha). When Rasulullah (sallallahu ‘alaihi wasallam) married Hazrat Khadijah (radhiyallahu ‘anha), she gave Hazrat Zaid (radhiyallahu ‘anhu) to Rasulullah (sallallahu ‘alaihi wasallam) as a gift.
Later on, when Rasulullah (sallallahu ‘alaihi wasallam) was bestowed with nubuwwah by Allah Ta‘ala, Hazrat Zaid bin Haarithah (radhiyallahu ‘anhu) brought imaan in him and embraced Islam. (Taareekh-ul-Khamees 2/73)
Hence, Hazrat Zaid bin Haarithah (radhiyallahu ‘anhu) was among the first Sahaabah who embraced Islam. He embraced Islam in his childhood at the hands of Rasulullah (sallallahu ‘alaihi wasallam). Initially, he was the slave of Rasulullah (sallallahu ‘alaihi wasallam), but after some time, Rasulullah (sallallahu ‘alaihi wasallam) freed him and had taken him as his son. He was thereafter well known by the name “Zaid bin Muhammed” (Zaid, the son of Muhammed).
However, Allah Ta‘ala later on revealed the following verse:
اُدۡعُوۡہُمۡ لِاٰبَآئِہِمۡ ہُوَ اَقۡسَطُ عِنۡدَ اللّٰہِ ۚ
Call them by (the names of) their fathers, it is more just in the sight of Allah Ta‘ala. (Surah Ahzaab v. 5)
Through this verse, Allah Ta‘ala prohibited considering the adopted son as one’s real son, and Allah Ta‘ala commanded that the adopted son should be attributed to his biological father. Hence, Rasulullah (sallallahu ‘alaihi wasallam) informed the ummah that Hazrat Zaid (radhiyallahu ‘anhu) is no longer his son, but his adopted son, and his father is Haarithah. Hence, Hazrat Zaid (radhiyallahu ‘anhu) should be referred to as “Zaid bin Haarithah”.
(Uyoon-ul-Athar 1/112, Saheeh Bukhaari #4782)
The Islam of Hazrat Suhaib bin Sinaan Roomi (radhiyallahu ‘anhu)
Hazrat Suhaib (radhiyallahu ‘anhu) hailed from an area that was in the vicinity of Mowsil. His father and uncle (father’s brother) were both appointed by Kisra (the Persian Emperor) as governors over the land of Ubullah.
On one occasion, the Romans launched an attack on this area. At that time, Hazrat Suhaib (radhiyallahu ‘anhu) was still a young boy. During the looting and plundering, they seized him as a captive and took him to Rome. He thus grew up in Rome, and this is the reason why he was famously known as ‘Suhaib Roomi’ (Suhaib the Roman).
Eventually, a person of the Banu Kalb tribe purchased him from the Romans and brought him to Makkah Mukarramah. After arriving in Makkah Mukarramah, Abdullah bin Jud’aan purchased him and set him free. (Usdul Ghaabah 3/38)
When Rasulullah (sallallahu ‘alaihi wasallam) commenced inviting towards Islam, Hazrat Suhaib (radhiyallahu ‘anhu) came to Daar-ul-Arqam to embrace Islam. Coincidentally, Hazrat Ammaar bin Yaasir (radhiyallahu ‘anhu) also arrived at the same time and embraced Islam with him at the hand of Rasulullah (sallallahu ‘alaihi wasallam).
The Islam of Hazrat Ammaar bin Yaasir (radhiyallahu ‘anhu)
Hazrat Ammaar bin Yaasir (radhiyallahu ‘anhu) says:
Hazrat Suhaib bin Sinaan (radhiyallahu ‘anhu) and I had come to Daar-e-Arqam at the same time. We met at the door of Daar-e-Arqam, while Rasulullah (sallallahu ‘alaihi wasallam) was inside. While at the door, I asked him, “What is your intention for coming here?” However, he responded, “You first tell me why you have come here.”
I replied, “I have come to Rasulullah (sallallahu ‘alaihi wasallam) to listen to his message.” Hazrat Suhaib (radhiyallahu ‘anhu) said, “I have also come with the very same intention.”
Thereafter, we both entered Daar-e-Arqam where Rasulullah (sallallahu ‘alaihi wasallam) presented the teachings of Islam to us and invited us to bring Imaan. Without any delay, we both accepted his invitation to Islam and were blessed with Imaan.
Hazrat Ammaar bin Yaasir (radhiyallahu ‘anhu) and Hazrat Suhaib bin Sinaan (radhiyallahu ‘anhu) were both among the first forty Sahaabah (radhiyallahu ‘anhum) to embrace Islam. (Tabaqaat Ibnu Sa’d 3/171)