Surah Al-Mursalat, Ayah 48

وَيْلٌ يَوْمَئِذٍ لِّلْمُكَذِّبِينَ

** (Woe that Day to the deniers!) **(41. Verily, those who had Taqwa, shall be amidst shades and springs.) (42. And fruits, such as they desire.) (43. "Eat and drink comfortably for that which you used to do.") (44. Verily, thus We reward the Muhsinin.) (45. Woe that Day to the deniers!) (46. Eat and enjoy yourselves for a little while. Verily, you are criminals.) (47. Woe that Day to the deniers!) (48. And when it is said to them: "Bow down yourself!" They bow not down.) (49. Woe that Day to the deniers!)(50. Then in what statement after this will they believe)

وَإِذَا قِيلَ لَهُمُ ارْ‌كَعُوا لَا يَرْ‌كَعُونَ (And when it is said to them, "Bow down", they do not bow down...77:48) According to most commentators, the word ruku' is used here in its primitive sense 'to bow down and submit'. The verse signifies that when they were told to submit to the Divine commands, they refused to comply. Some scholars take the word ruku` in its technical sense and interpret the verse to signify 'when they are called to prayer, they refused to pray.' The ruku` is a part of the prayer, but it refers here to the whole prayer. [ Ruh ]

When a man is confronted with the horrors of the Hereafter, he will find himself helpless. At that time, those who were wont to speak as if their vocabulary was inexhaustible, will be rendered speechless.