Do you not see that the ships sail in the ocean by the grace of God, that He may show you some of His glories. Verily there are signs in this for those who are constant and give thanks. 31 When the waves engulf them like shadows [of death], they call to God, sincere [at that moment] in their faith in Him alone: but as soon as He has brought them safe ashore, only some of them take the right course. And none denies Our signs save the perfidious and ungrateful person. 32 O mankind! do your duty to your Lord, and fear (the coming of) a Day when no father can avail aught for his son, nor a son avail aught for his father. Verily, the promise of Allah is true: let not then this present life deceive you, nor let the chief Deceiver deceive you about Allah. 33 Surely Allah alone has the knowledge of the Hour. It is He Who sends down the rain and knows what is in the wombs, although no person knows what he will earn tomorrow, nor does he know in which land he will die. Indeed, Allah is All-Knowing, All-Aware. 34