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 And when waves come over them like canopies, they supplicate Allah, sincere to Him in religion. But when He delivers them to the land, there are [some] of them who are moderate [in faith]. And none rejects Our signs except everyone treacherous and ungrateful. 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 Only God has the knowledge of the Hour. He sends rain from the heavens, and knows what is in the mothers' wombs. No one knows what he will do on the morrow; no one knows in what land he will die. Surely God knows and is cognisant. 34