وَمَا كُنتَ تَرْجُو أَن يُلْقَى إِلَيْكَ الْكِتَابُAnd you were not expecting that the Book would be sent down to you,`Before the revelation was sent down to you, you did not expect that revelation would be sent down to you.'إِلاَّ رَحْمَةً مِّن رَّبِّكَbut it is a mercy from your Lord.means, `but revelation has been sent down to you from Allah as a mercy to you and to mankind because of you. Since Allah has granted you this great blessing,'فَلَ تَكُونَنَّ ظَهِيرًاSo never be a supporter, i.e., a helper,لِّلْكَافِرِينَof the disbelievers.rather, separate from them, `express your hostility towards them and oppose them.