Surat Yā-Sīn - سورة يس

وَإِذَا قِيلَ لَهُمُ اتَّقُوا مَا بَيْنَ أَيْدِيكُمْ وَمَا خَلْفَكُمْ لَعَلَّكُمْ تُرْحَمُونَ

Muhsin Khan: And when it is said to them: "Beware of that which is before you (worldly torments), and that which is behind you (torments in the Hereafter), in order that you may receive Mercy (i.e. if you believe in Allah's Religion Islamic Monotheism, and avoid polytheism, and obey Allah with righteous deeds).