Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Our Lord will reveal His Shin, and then all believers, men and women, will prostrate themselves before Him, but there will remain those who used to prostrate in the worldly life for showing off and gaining good reputation. Such people will try to prostrate (in that situation) but their backs will be as stiff as if it is one bone (a single vertebra)."
عن أبي سعيد الخدري -رضي الله عنه- مرفوعاً: «يكشِف ربُّنا عن ساقِه، فيسجدُ له كلُّ مؤمنٍ ومؤمنةٍ، فيبقى كلُّ مَن كان يسجدُ في الدنيا رياءً وسُمْعةً، فيذهبُ ليسجدَ، فيعودَ ظهرُه طبقًا واحدًا».
شرح الحديث :
The Lord, Glorified and Exalted, will reveal His noble Shin on the Day of Judgment, and every believer, male and female, will prostrate to Him. As for the hypocrites who used to prostrate to Allah in the worldly life so as to be seen by people, they will not be able to prostrate because their backs will be made of one vertebra or one straight bone. They will not be able to bend nor prostrate, because they did not really prostrate to Allah in the worldly life, rather they only prostrated to their worldly purposes. It is not permissible to interpret Allah's Shin as hardship, distress and so on. Rather it is obligatory to affirm this attribute for Allah, the Almighty, without asking 'how', and without drawing resemblance or similitude, and without stripping it of its true meaning.