Allah informs of what he has waiting for those who disbelieve in Him from His creatures of chains, iron collars and Sa`ir. Sa`ir is the flame and fire of the Hell. This is as Allah says,

﴿إِذِ الاٌّغْلَـلُ فِى أَعْنَـقِهِمْ والسَّلَـسِلُ يُسْحَبُونَ - فِى الْحَمِيمِ ثُمَّ فِى النَّارِ يُسْجَرُونَ ﴾

(When iron collars will be rounded over their necks, and the chains, they shall be dragged along, in the boiling water, then they will be burned in the Fire.) (40:71,72) After mentioning the blazing Fire He has prepared for these wretched people, Allah goes on to say,

﴿إِنَّ الاٌّبْرَارَ يَشْرَبُونَ مِن كَأْسٍ كَانَ مِزَاجُهَا كَـفُوراً ﴾

(Verily, the Abrar (righteous believers) shall drink of a cup mixed with Kafur.) The properties of the Kafur (camphor) are well known; cooling, having a nice fragrance and in addition to this its taste will be delicious in Paradise. Al-Hasan said, "The coolness of the camphor will be in the pleasantness of ginger.'' Thus Allah said,

﴿عَيْناً يَشْرَبُ بِهَا عِبَادُ اللَّهِ يُفَجِّرُونَهَا تَفْجِيراً ﴾

(A spring wherefrom the servants of Allah will drink, causing it to gush forth abundantly.) meaning, this (drink) that will be mixed for these righteous people will be taken from Kafur, which is a spring that Allah's close servants will drink directly from, without it being mixed with anything, and they will drink to their fill from it. The word Yashrabu (to drink) includes the meaning of Yarwa (to quench one's thirst). Allah then says,

﴿يُفَجِّرُونَهَا تَفْجِيراً﴾

(causing it to gush forth abundantly (Tafjir).) meaning, they will have control of it however and wherever they wish. They will have access to it from their castles, their homes, their sitting rooms and their residences. At-Tafjir means to cause to gush forth or flow out. This is as Allah says,

﴿وَقَالُواْ لَن نُّؤْمِنَ لَكَ حَتَّى تَفْجُرَ لَنَا مِنَ الاٌّرْضِ يَنْبُوعًا ﴾

(And they say: "We shall not believe in you until you cause a spring to gush forth from the earth for us.) (17:90) And Allah says,

﴿وَفَجَّرْنَا خِلَـلَهُمَا نَهَراً﴾

(We caused a river to gush forth in the midst of them.) (18:33) Mujahid said,

﴿يُفَجِّرُونَهَا تَفْجِيراً﴾

(causing it to gush forth abundantly.) "This means that they will divert it to wherever they wish.'' `Ikrimah and Qatadah both made similar statements. Ath-Thawri said, "They will cause it to flow wherever they wish.''