Bilaal: “He did not care what happened to him for the sake of Allah and his people did not care what happened to him”
Question

                I would like an explanation of this hadith:
“There was none of them who did not do what they wanted them to do, except for Bilaal. 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 whilst he was saying, Ahad, Ahad (One, One).” Narrated by Ahmad.

What is meant by the words: “He did not care what happened to him for the sake of Allah and his people did not care what happened to him”?
Praise be to Allah.
      Firstly:

    Ibn Maajah (150) 
    and Ahmad (3822) narrated that ‘Abdullah ibn Mas‘ood said: The first people 
    to declare their Islam publicly were seven: the Messenger of Allah 
    (blessings and peace of Allah be upon him), Abu Bakr, ‘Ammaar and his mother 
    Sumayyah, Suhayb, Bilaal and al-Miqdaad. With regard to the Messenger of 
    Allah, Allah protected him through his paternal uncle Abu Taalib. With 
    regard to Abu Bakr, Allah protected him through his people. As for the rest, 
    the mushrikoon 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 Bilaal. 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 whilst he was saying, Ahad, Ahad (One, One). 

    Classed as saheeh by al-Albaani in Saheeh Ibn Maajah. 

    As-Sindi (may Allah have mercy on him) said: 

    The words “He did not care what happened to him for the sake 
    of Allah” mean that he thought little of himself for the sake of Allah. 

    What is meant that he (may Allah be pleased with him) felt 
    himself to be very insignificant, so he did not care what happened to him 
    for the sake of Allah. It was all the same to him whether they beat him or 
    reviled him or killed him; all of that was of little significance to him for 
    the sake of Allah. So long as he was on the path of Allah and earning His 
    pleasure, he did not care, and he regarded everything, in comparison to the 
    pleasure of Allah, as worthless and of little value, and he thought it was 
    worth offering his soul willingly for the sake of Allah and not withholding 
    it. 

    Because he was so strongly committed and steadfast, he did 
    not give in to them with regard to anything that they wanted from him, and 
    he kept repeating the word of Tawheed which increased them in their rage and 
    fury towards him, so they increased their torture of him, and that increased 
    him in strength, faith, steadfastness and certainty – may Allah be pleased 
    with him. 

    The words “and his people did not care what happened to him” 
    mean that he had no value in their eyes and they did not hold him in any 
    esteem, because he was a black slave who disbelieved in their gods and 
    stubbornly opposed them. He had no power or tribe to protect him or defend 
    him, so they tormented him even more and they gave him to the children who 
    started taking him around in the streets of Makkah, to cause further 
    suffering to him and humiliate him publicly, until Allah saved him from them 
    by means of Abu Bakr as-Siddeeq (may Allah be pleased with him), who bought 
    him and manumitted him. 

    Al-Bukhaari (3574) narrated that Jaabir ibn ‘Abdullah (may 
    Allah be pleased with him) said: ‘Umar used to say: Abu Bakr is our master, 
    and he manumitted our master – meaning Bilaal. 

    And Allah knows best.