Back 
Surah 17. Al-Israa
Ayah 66 - 68
٦٦. رَّبُّكُمُ ٱلَّذِى يُزْجِى لَكُمُ ٱلْفُلْكَ فِى ٱلْبَحْرِ لِتَبْتَغُوا۟ مِن فَضْلِهِۦٓ ۚ إِنَّهُۥ كَانَ بِكُمْ رَحِيمًا
٦٧. وَإِذَا مَسَّكُمُ ٱلضُّرُّ فِى ٱلْبَحْرِ ضَلَّ مَن تَدْعُونَ إِلَّآ إِيَّاهُ ۖ فَلَمَّا نَجَّىٰكُمْ إِلَى ٱلْبَرِّ أَعْرَضْتُمْ ۚ وَكَانَ ٱلْإِنسَـٰنُ كَفُورًا
٦٨. أَفَأَمِنتُمْ أَن يَخْسِفَ بِكُمْ جَانِبَ ٱلْبَرِّ أَوْ يُرْسِلَ عَلَيْكُمْ حَاصِبًا ثُمَّ لَا تَجِدُوا۟ لَكُمْ وَكِيلًا
[66-68] Your (real) Lord is the One, Who drives your ship across the sea82 so that you may seek His bounty.83 The fact is that He is very merciful towards you. When a misfortune befalls you on the sea, all of those whom you invoke for help fail you but He (is there to help you84 ): yet when He brings you safe to land, you turn away from Him. Indeed man is very ungrateful. What, do you feel quite secure that sometimes Allah would not cause you to sink underground even on land, or send a deadly whirlwind charged with stones toward you, and you may not find anyone to protect you from it?
82This passage (vv. 66-72) is closely connected with the previous one. It tells man that if he wants to protect himself from the allurements, temptations and false promises of Satan who has been his avowed enemy from the day of his creation, he should recognize his real Lord and be steadfast in His obedience. Satan intends to prove that man is not worthy of the honor with which Allah has blessed him. Therefore if he follows any other way he cannot escape the snares of Satan.
In this passage, arguments of Tauhid have been put forward in order to make man steadfast in his Faith and refrain from shirk.
83That is, "Try to avail of the economic, social, educational and intellectual benefits which are provided by the sea voyages."
84That is, "This is a proof of the fact that your real nature knows no other Lord than Allah, and you feel in the depths of your hearts that He alone possesses the real power of every gain or loss. Had it not been so, man would never have invoked Allah at the time when he realized that no other helper could remove his misfortune."