Have you not seen how the ships sail on the sea by God's grace so that He may show you some of His signs? Surely therein are signs for every steadfast, thankful person. 31 And when a wave covers them like shades (i.e. like clouds or the mountains of sea-water), they invoke Allah, making their invocations for Him only. But when He brings them safe to land, there are among them those that stop in the middle, between (Belief and disbelief). But none denies Our Signs except every perfidious 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