يَا أَيُّهَا الَّذِينَ آمَنُوا قُوا أَنفُسَكُمْ وَأَهْلِيكُمْ نَارًا وَقُودُهَا النَّاسُ وَالْحِجَارَةُ عَلَيْهَا مَلَائِكَةٌ غِلَاظٌ شِدَادٌ لَّا يَعْصُونَ اللَّهَ مَا أَمَرَهُمْ وَيَفْعَلُونَ مَا يُؤْمَرُونَ (6)
(66:6) Believers, guard yourselves and your kindred against a Fire whose fuel is human beings and stones, *16 a Fire held in the charge of fierce and stern angels who never disobey what He has commanded them, and always do what they are bidden. *17
*16) Thts verse tells that a person's responsibility is not confined to making effort to save himself from the punishment of God but it is also his responsibility that he should so educate and train to the best of his ability members of his family also to become Allah's favourite servants, who have been entrusted to his care in the natural process of life; and if they might be following a path to Hell, he should try. as far as he can, to correct them. His concern should not only be that his children should lead a happy and prosperous life in the world but; more than that, he should be anxious to see that they do not become fuel of Hell in the Hereafter. According to a tradition reported in Bukhiiri by Hadrat `Abdullah bin 'Umar, the Holy Prophet (upon whom be peace) said: "Each one of you is a herdsman and is accountable with regard to his herd: the ruler is a herdsman and is accountable with regard to his subjects; the man is a herdsman of his family and is accountable with regard to them; and the woman is a herdsman of her husband's house and his children and is accountable with regard to them."
Whose fuel...stone" probably implies coal. Ibn Mas' ud, Ibn 'Abbas, Mujahid, Imam Muhammad al-Baqir and Suddi say that this will be brimstone.
*17) That is, they will enforce on every culprit precisely the same punishment which they will be commanded to enforce on him without making any alteration in it, or showing any pity for him.