Tahajjud obligation for him

وَمِنَ ٱلَّيْلِ فَتَهَجَّدْ بِهِۦ نَافِلَةًۭ لَّكَ عَسَىٰٓ أَن يَبْعَثَكَ رَبُّكَ مَقَامًۭا مَّحْمُودًۭا

And pray in the small watches of the morning: (it would be) an additional prayer (or spiritual profit) for thee: soon will thy Lord raise thee to a Station of Praise and Glory!

فَٱصْبِرْ عَلَىٰ مَا يَقُولُونَ وَسَبِّحْ بِحَمْدِ رَبِّكَ قَبْلَ طُلُوعِ ٱلشَّمْسِ وَقَبْلَ غُرُوبِهَا ۖ وَمِنْ ءَانَآئِ ٱلَّيْلِ فَسَبِّحْ وَأَطْرَافَ ٱلنَّهَارِ لَعَلَّكَ تَرْضَىٰ

Therefore be patient with what they say, and celebrate (constantly) the praises of thy Lord, before the rising of the sun, and before its setting; yea, celebrate them for part of the hours of the night, and at the sides of the day: that thou mayest have (spiritual) joy.

قُمِ ٱلَّيْلَ إِلَّا قَلِيلًۭا

Stand (to prayer) by night, but not all night,-

۞ إِنَّ رَبَّكَ يَعْلَمُ أَنَّكَ تَقُومُ أَدْنَىٰ مِن ثُلُثَىِ ٱلَّيْلِ وَنِصْفَهُۥ وَثُلُثَهُۥ وَطَآئِفَةٌۭ مِّنَ ٱلَّذِينَ مَعَكَ ۚ وَٱللَّهُ يُقَدِّرُ ٱلَّيْلَ وَٱلنَّهَارَ ۚ عَلِمَ أَن لَّن تُحْصُوهُ فَتَابَ عَلَيْكُمْ ۖ فَٱقْرَءُوا۟ مَا تَيَسَّرَ مِنَ ٱلْقُرْءَانِ ۚ عَلِمَ أَن سَيَكُونُ مِنكُم مَّرْضَىٰ ۙ وَءَاخَرُونَ يَضْرِبُونَ فِى ٱلْأَرْضِ يَبْتَغُونَ مِن فَضْلِ ٱللَّهِ ۙ وَءَاخَرُونَ يُقَٰتِلُونَ فِى سَبِيلِ ٱللَّهِ ۖ فَٱقْرَءُوا۟ مَا تَيَسَّرَ مِنْهُ ۚ وَأَقِيمُوا۟ ٱلصَّلَوٰةَ وَءَاتُوا۟ ٱلزَّكَوٰةَ وَأَقْرِضُوا۟ ٱللَّهَ قَرْضًا حَسَنًۭا ۚ وَمَا تُقَدِّمُوا۟ لِأَنفُسِكُم مِّنْ خَيْرٍۢ تَجِدُوهُ عِندَ ٱللَّهِ هُوَ خَيْرًۭا وَأَعْظَمَ أَجْرًۭا ۚ وَٱسْتَغْفِرُوا۟ ٱللَّهَ ۖ إِنَّ ٱللَّهَ غَفُورٌۭ رَّحِيمٌۢ

Thy Lord doth know that thou standest forth (to prayer) nigh two-thirds of the night, or half the night, or a third of the night, and so doth a party of those with thee. But Allah doth appoint night and day in due measure He knoweth that ye are unable to keep count thereof. So He hath turned to you (in mercy): read ye, therefore, of the Qur'an as much as may be easy for you. He knoweth that there may be (some) among you in ill-health; others travelling through the land, seeking of Allah's bounty; yet others fighting in Allah's Cause, read ye, therefore, as much of the Qur'an as may be easy (for you); and establish regular Prayer and give regular Charity; and loan to Allah a Beautiful Loan. And whatever good ye send forth for your souls ye shall find it in Allah's Presence,- yea, better and greater, in Reward and seek ye the Grace of Allah: for Allah is Oft-Forgiving, Most Merciful.

وَمِنَ ٱلَّيْلِ فَٱسْجُدْ لَهُۥ وَسَبِّحْهُ لَيْلًۭا طَوِيلًا

And part of the night, prostrate thyself to Him; and glorify Him a long night through.