Zayd ibn Arqam
He was the first person in Islam to give his home for the first Salat (ritual prayer) in Islam, which was led by Muhammad. It was in his house where Caliph Umar converted to Islam. He gave allegiance to Abu Bakr, when Ali did so.
After the Invasion of Banu Mustaliq 'Abdullāh ibn ‘Ubayy, who was referred to as the head of the "Hypocrites" (munāfiqūn), was furious for the challenge which the Muslims showed towards the hostile plans and intrigues woven behind closed doors, and swore "the most honourable will expel the meanest out of Madinah," and added: "They (the Muslims) have outnumbered and shared us our land. If you fatten your dog, it will eat you." Zayd ibn Arqam narrated this to the Prophet who then asked for Abdullāh ibn ‘Ubayy's presence. ibn ‘Ubayy swore oaths denying he had stated something like this and because of this he was let go. But later on the testimony of Zayd ibn Arqam was verified by the revelation of Surah Al-Munāfiqūn.
The hadith of the two weighty things
When Zaid was older, he retold the hadith of the two weighty things, during the rule of the Umayyad Caliphate. One version is quoted in Sahih Muslim where he, after being asked several times, tells about the event and unwillingly concludes that Muhammad's wives are not part of the Ahl ul-Bayt. In another version, he gives a more vague answer.
On the aftermath of the Battle of Karbala
After reaching Kufa, the womenfolk and captives of Husayn ibn Ali’s family and the heads of the victims were presented to Ibn Ziyad, and the head of Al-Hussein was placed in a tray in front of him in a court ceremony crowded with nobles and spectators. Ibn Ziyad, having a cane in his hand, struck the head of Al-Hussein over and over. Zayd Bin Arqam, an old Companion of the Prophet present in the court, not aware of what had happened, recognized Al-Hussein’s face. Stricken by shock and grief, he shouted to Ibn Ziyad: “Remove your cane off this face! By God, how many times have I seen the Prophet kissing this face”, and he burst into tears. Ibn Ziyad was livid with rage. He retorted: “Ibn Ziyad (Ubaydallah) said, “May God make your eyes weep, for by God, if it were not for the fact that you are an old man, who has become silly and your mind has left you, I would cut off your head”. So, Zaid Bin Arqam stood up and left the court.
- Tarikh al-Yaqubi, as quoted in Peshawar Nights on Al-islam.org . Also, a list composed of sources such as Ibn Hajar Asqalani and Baladhuri, each in his Ta'rikh, Muhammad Bin Khawind Shah in his Rauzatu's-Safa, Ibn Abdu'l-Birr in his Isti'ab
- Qadhi, Yasir. A Mercy to Mankind
- Kitab al-Irshad' by Al-Mufid page 338 in