Translation of the verse 106 from Surah An-Nahl : Number of verses 128 - - page 279 - Part 14.
Whoever disbelieved in Allah after his belief, except him who is forced thereto and whose heart is at rest with Faith but such as open their breasts to disbelief, on them is wrath from Allah, and theirs will be a great torment.
Whoever disbelieves in Allah after his belief... except for one who is forced [to renounce his religion] while his heart is secure in faith. But those who [willingly] open their breasts to disbelief, upon them is wrath from Allah, and for them is a great punishment;
(16:106) Whoso is forced to disbelieve after believing, while his heart is convinced of the Faith, (he shall be absolved) but whosoever accepts disbelief willingly, he incurs Allah's wrath, and there is severe torment for all such people. *109
*109) This verse deals with the case of those Muslims who were being persecuted with cruelty and were being-subjected to unbearable torments to force them to give up their Faith. They are being told that if at any time they are forced to utter words of disbelief to save their lives, when in fact in their hearts they are secure against disbelief, they will be pardoned. On the other hand, if they accepted unbelief from the core of their hearts, they shall not escape the torment of Allah even if they succeed in saving their lives.
It does not, however, mean that one should utter words of disbelief to save one's life. This is merely a permission but not the ideal thing for a Believer. According to this permission if one utters such a thing, he shall not be taken to account. In fact, the ideal for a Believer is to utter words of truth in any case whether his body is cut into pieces. There are instances which show that during the period of the Holy Prophet some acted upon the ideal while others took advantage of the permission. There was Khabbab bin Art (May Allah be pleased with him) who was made to lie on embers of fire until the fire was extinguished by the melting of his fat, but he remained firm in his Faith. Then there was Bilal Habashi (May Allah be pleased with him) who was made to put on an armour and stand in the scorching heat. Then he was dragged on the burning sand but he went on saying, "Allah is one." There was another Believer, Habib Gin Zaid bin `Asim, whose limbs were cut one by one by the order of Musailimah, the Liar. Each time his limb was severed it was demanded of him that he should acknowledge the Liar as a prophet but each time he refused to bear witness to his claim of prophethood until he breathed his last. On the other hand, there was the instance of Ammar bin Yasir (May Allah be pleased with him) whose parents were mercilessly butchered before his eyes. After this he himself was put to such unbearable torture that, in order to save his life, he had to utter the same words of unbelief that were demanded of him. Afterwards when he came crying to the Holy Prophet, he said, "O Messenger of Allah, they did not let me go until I spoke evil of you and praised their deities" . The Holy Prophet asked him, "How do you feel about this, in your heart?" He replied humbly, "My heart is fully convinced of the Faith." At this the Holy Prophet replied, "If they put you to the same torture again, you may utter the same words" .