لَوْ أَرَدْنَآ أَن نَّتَّخِذَ لَهْوًا لَّٱتَّخَذْنَـٰهُ مِن لَّدُنَّآ إِن كُنَّا فَـٰعِلِينَ
Had We intended to take a diversion, We could have taken it from [what is] with Us - if [indeed] We were to do so.
The Prophets
لَوْ أَرَدْنَآ أَن نَّتَّخِذَ لَهْوًا لَّٱتَّخَذْنَـٰهُ مِن لَّدُنَّآ إِن كُنَّا فَـٰعِلِينَ
Had We intended to take a diversion, We could have taken it from [what is] with Us - if [indeed] We were to do so.
Nearby ayahs help place verse 21:17 in sequence and meaning.
فَمَا زَالَت تِّلْكَ دَعْوَىٰهُمْ حَتَّىٰ جَعَلْنَـٰهُمْ حَصِيدًا خَـٰمِدِينَ
And that declaration of theirs did not cease until We made them [as] a harvest [mowed down], extinguished [like a fire].
وَمَا خَلَقْنَا ٱلسَّمَآءَ وَٱلْأَرْضَ وَمَا بَيْنَهُمَا لَـٰعِبِينَ
And We did not create the heaven and earth and that between them in play.
بَلْ نَقْذِفُ بِٱلْحَقِّ عَلَى ٱلْبَـٰطِلِ فَيَدْمَغُهُۥ فَإِذَا هُوَ زَاهِقٌ ۚ وَلَكُمُ ٱلْوَيْلُ مِمَّا تَصِفُونَ
Rather, We dash the truth upon falsehood, and it destroys it, and thereupon it departs. And for you is destruction from that which you describe.
وَلَهُۥ مَن فِى ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ ۚ وَمَنْ عِندَهُۥ لَا يَسْتَكْبِرُونَ عَنْ عِبَادَتِهِۦ وَلَا يَسْتَحْسِرُونَ
To Him belongs whoever is in the heavens and the earth. And those near Him are not prevented by arrogance from His worship, nor do they tire.