Bilal bin Rabah, his hardships and love for Tawheed and Prophet peace be upon him.
1. Ata al Khurasani said:
كنت عند سعيد بن المسيب فذكرت بلالا فقال : كان شحيحا على دينه وكان يعذب في الله ، وكان يعذب على دينه فإذا أراد المشركون أن يقاربهم قال الله الله
“I was with Sa’id ibn al-Musayyib, and I mentioned Bilal, so he said: ‘He would zealously guard his religion, and he would be tortured for the sake of Allah. He would be tortured for his religion, so when the polytheists wanted to get close to him (for torture), he would say: “Allah! Allah!”‘
(Al Jame Shuab al Iman by al Bayhaqi vol 3 page 171 the researcher said the narrators are all trustworthy)
2. Ibn Katheer mentioned about Bilal may Allah be pleased him:
“When they were inflicting all sorts of torture on him, even placing a huge rock on his chest in the intense heat and telling him to admit others as partners with Allah. He refused, saying, Ahad, Ahad “Alone, Alone.” And he said, “By Allah, if I knew any word more annoying to you than this, I would say it.” may Allaah be pleased with him.
[Tafsir of Surah an-Nahl verse 106.]3. Ibn Abdil Barr mentioned from Mujahid:
أنهم كانوا يطوفون به والحبل في عنقه بين أخشبي مكة
Polytheists would parade Bilal around with a rope around his neck, between the hills of Mecca.”
al Istiaab 1/179
4. Dhahabi mentioned from Ibn Uyaynah:
عَنْ إِسْمَاعِيْلَ، عَنْ قَيْسٍ، قَالَ:
اشْتَرَى أَبُو بَكْرٍ بِلاَلاً وَهُوَ مَدْفُوْنٌ فِي الحِجَارَةِ بِخَمْسِ أَوَاقٍ ذَهَباً.
فَقَالُوا: لَوْ أَبَيْتَ إِلاَّ أُوْقِيَّةً لَبِعْنَاكَهُ.
قَالَ: لَوْ أَبَيْتُم إِلاَّ مَائَةَ أُوْقِيَّةٍ لأَخَذْتُهُ.
إِسْنَادُهُ قَوِيٌّ.
Who narrated from Ismail from Qays:
Abu Bakr purchased Bilal while he was buried in the rocks for five awqiyahs of gold.
They said, “If you had only offered one awqiyah, we would have sold him to you.”
He said, “If you had only asked for one hundred awqiyahs, I would have taken him.”
(Dhahabi said) Its chain of narration is strong.
(Siyar Ailam al Nubala under the biography of Bilal bin Rabah radhiAllahanho)
5. Abdullah ibn Masud said about some sahaba:
“… The idolators seized them and made them wear coats of chain-mail and exposed them to the intense heat of the sun. There was none of them who did not do what they wanted them to do, except for Bilal. He did not care what happened to him for the sake of Allah, and his people did not care what happened to him. Then they gave him to the children who took him around in the streets of Makkah while he was saying, ‘Ahad, Ahad (One, One).'”
Grade : Hasan (Darussalam)
Ibn Maja Hadith 150
6. Bilal’s Adhan after the death of the Prophet (peace be upon him).
Al-Bukhari relates from Aslam Al Adawiyy:
قدمنَا الشَّام مَعَ عمر، فَأذن بِلَال، فَذكر النَّاس النَّبِي -صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ- فَلم أر يَوْمًا أَكثر باكيا مِنْهُ
We came to al Sham with Umar and Bilal made the Adhan. When people heard the adhan of Bilal people remembered the Prophet (peace be upon him) and started weeping. Aslam said: I have never seen a day with such multitudes of people wailing.
(Tareekh al Awsat by al Bukhari 2/139, Abu Dawud narrated in al Zuhud page 238 the researchers authenticated the narrators.).
7. Imam al Bukhari said in the book of Companions of the Prophet peace be upon him.
باب مَنَاقِبُ بِلاَلِ بْنِ رَبَاحٍ مَوْلَى أَبِي بَكْرٍ رضى الله عنهما
وَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «سَمِعْتُ دَفَّ نَعْلَيْكَ بَيْنَ يَدَيَّ فِي الْجَنَّةِ
حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ أَبِي سَلَمَةَ، عَنْ مُحَمَّدِ بْنِ الْمُنْكَدِرِ، أَخْبَرَنَا جَابِرُ بْنُ عَبْدِ اللَّهِ ـ رضى الله عنهما ـ قَالَ كَانَ عُمَرُ يَقُولُ أَبُو بَكْرٍ سَيِّدُنَا، وَأَعْتَقَ سَيِّدَنَا. يَعْنِي بِلاَلاً.
Chapter: The merits of Bilal bin Rabah, the freed slave of Abu Bakr may Allah be pleased with both.
The Prophet (peace be upon him) said (to Bilal) “I heard the sound of your shoes in Paradise just in front of me.”
Narrated Jabir bin `Abdullah:
`Umar used to say, “Abu Bakr is our chief, and he manumitted our chief,” meaning Bilal.
(Sahih al-Bukhari 3754)
Islam didn’t come to you in a plate. May Allah be pleased with him.