Az-Zumar 39:13

Say: "Verily, if I disobey my Lord, I am afraid of the torment of a great Day. (13)Say: "Allah Alone I worship by doing religious deeds sincerely for His sake only. (14)"So, worship what you like besides Him." Say: "The losers are those who will lose themselves and their families on the Day of Resurrection. Verily, that will be a manifest loss! (15)They shall have coverings of Fire, above them and covering (of Fire) beneath them. With this Allah frightens His servants: "O My servants, therefore have Taqwa of Me! (16)

Creating Fear of the Punishment of Allah

Allah says, say O Muhammad, even though you are the Messenger of Allah:

إِنِّي أَخَافُ إِنْ عَصَيْتُ رَبِّي عَذَابَ يَوْمٍ عَظِيمٍ

(Verily, if I disobey my Lord, I am afraid of the torment of a great Day.) meaning the Day of Resurrection. This is a conditional sentence, and if what is referred to here applies to the Prophet ﷺ, it applies even more so to others,

قُلِ اللَّهَ أَعْبُدُ مُخْلِصًا لَهُ دِينِي - فَاعْبُدُوا مَا شِئْتُمْ مِنْ دُونِهِ ۗ

(Say: "Allah Alone I worship by doing religious deeds sincerely for His sake only. So, worship what you like besides Him.") This is also a threat, and a disowning of them.

قُلْ إِنَّ الْخَاسِرِينَ

(Say: "The losers...") means, the greatest losers of all,

الَّذِينَ خَسِرُوا أَنْفُسَهُمْ وَأَهْلِيهِمْ يَوْمَ الْقِيَامَةِ

(are those who will lose themselves and their families on the Day of Resurrection.) means, they will be separated and will never meet again, whether their families have gone to Paradise and they have gone to Hell, or all of them have gone to Hell, they will never meet or feel happiness again.

أَلَا ذَٰلِكَ هُوَ الْخُسْرَانُ الْمُبِينُ

(Verily, that will be a manifest loss!) means, this is the clearest and most obvious loss. Then He describes their state in the Fire:

لَهُمْ مِنْ فَوْقِهِمْ ظُلَلٌ مِنَ النَّارِ وَمِنْ تَحْتِهِمْ ظُلَلٌ ۚ

(They shall have coverings of Fire, above them and covering (of Fire) beneath them.) This is like the Ayat:

لَهُمْ مِنْ جَهَنَّمَ مِهَادٌ وَمِنْ فَوْقِهِمْ غَوَاشٍ ۚ وَكَذَٰلِكَ نَجْزِي الظَّالِمِينَ

(Theirs will be a bed of Hell (Fire), and over them coverings (of Hell-fire). Thus do We recompense the wrongdoers)(7:41)

يَوْمَ يَغْشَاهُمُ الْعَذَابُ مِنْ فَوْقِهِمْ وَمِنْ تَحْتِ أَرْجُلِهِمْ وَيَقُولُ ذُوقُوا مَا كُنْتُمْ تَعْمَلُونَ

(On the Day when the torment (Hell-fire) shall cover them from above them and from underneath their feet, and it will be said: "Taste what you used to do.")(29:55)

ذَٰلِكَ يُخَوِّفُ اللَّهُ بِهِ عِبَادَهُ ۚ

(With this Allah frightens His servants:) means, Allah tells us about this, which will undoubtedly come to pass, to frighten His servants, so that they will keep away from unlawful things and from sin.

يَا عِبَادِ فَاتَّقُونِ

(O My servants, therefore have Taqwa of Me!) means, 'fear My wrath, My anger, My punishment and My vengeance.'