Overall meaning : Having thus revealed Satan’s bitter enmity to Adam’s descendants, the Almighty proceeds to point out some of His countless blessings upon them, saying: It is your Lord alone, mankind, who makes the ships sail across the sea for you so that you may seek of His bounty and sustenance through trade. Surely He is ever merciful to you. When a misfortune befalls you at sea and you face certain death by drowning, you forget about all the false gods you worship and turn sincerely to Allah alone to relieve you of the affliction that has best you; yet when He brings you safely to land, you turn away from giving thanks to Him and from worshipping Him alone. Man is ever ungrateful to his Lord despite the countless favours He constantly bestows on him.
The Almighty then proclaims that nothing whatsoever in the sea or the land, or anywhere else for that matter, can in the least frustrate His will: Do you, then, feel ever secure that He will not cause the earth to cleave asunder and swallow you up if you survive at sea—for He is perfectly capable of destroying you both at sea and on land—or rain stones down upon you and destroy you? You will not find then anyone to protect you against His punishment. Or do you feel secure that He will not send you back to sea once again, and let loose upon you a raging storm and drown you for your unbelief? You will not then find anyone to help you against Us for destroying you.