إِنَّهُمۡ إِن يَظۡهَرُواْ عَلَيۡكُمۡ يَرۡجُمُوكُمۡ أَوۡ يُعِيدُوكُمۡ فِي مِلَّتِهِمۡ وَلَن تُفۡلِحُوٓاْ إِذًا أَبَدٗا ٢٠
Indeed, if they come to know of you, they will stone you or return you to their religion. And never would you succeed, then - ever."
Translation: Saheeh International (English)
Each word's meaning and sound
If your people discover you and find out where your whereabouts, they will kill you by stoning you, or they will force you to return to their deviated creed that you used to follow before Allah favoured you by guiding you to the true religion. If you return to that you will never succeed - not in this world nor in the Hearafter. Instead, you will suffer a great loss in both places on account of your leaving the true religion to which Allah had guided you and your returning to that deviated creed.
Al-Mukhtasar in interpreting the Noble Quran