In the name of Allah, the Gracious, the Merciful
Al-Nawawi records in his book Riyad al-Salihin:
Abu Huraira reported:
أَوْصَانِي خَلِيلِي (النبي صلى الله عليه وسلم) بِثَلَاثٍ لَا أَدَعُهُنَّ حَتَّى أَمُوتَ صَوْمِ ثَلَاثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَصَلَاةِ الضُّحَى وَنَوْمٍ عَلَى وِتْرٍ
My dear friend the Prophet, peace and blessings be upon him, advised me to do three deeds and I will never abandon them until I die: to fast three days of every month, to perform forenoon prayer, and to sleep after performing the witr prayer.
Source: Ṣaḥīḥ al-Bukhārī 1124, Grade: Muttafaqun Alayhi
Al-Nawawi comments on this tradition, saying:
وَالإيتَارُ قَبْلَ النَّوْمِ إنَّمَا يُسْتَحَبُّ لِمَنْ لاَ يَثِقُ بِالاسْتِيقَاظِ آخِرَ اللَّيل فإنْ وَثِقَ فَآخِرُ اللَّيل أفْضَلُ
To perform witr prayer before sleeping is only recommended for one who is not confident he will wake up at the end of the night. If he is confident he will wake up, it is better to pray it at the end of the night.
Abu Dharr reported: The Prophet, peace and blessings be upon him, said:
يُصْبِحُ عَلَى كُلِّ سُلَامَى مِنْ أَحَدِكُمْ صَدَقَةٌ فَكُلُّ تَسْبِيحَةٍ صَدَقَةٌ وَكُلُّ تَحْمِيدَةٍ صَدَقَةٌ وَكُلُّ تَهْلِيلَةٍ صَدَقَةٌ وَكُلُّ تَكْبِيرَةٍ صَدَقَةٌ وَأَمْرٌ بِالْمَعْرُوفِ صَدَقَةٌ وَنَهْيٌ عَنْ الْمُنْكَرِ صَدَقَةٌ وَيُجْزِئُ مِنْ ذَلِكَ رَكْعَتَانِ يَرْكَعُهُمَا مِنْ الضُّحَى
Upon every one of your joints in the morning is charity due. Every glorification of Allah is charity. Every praise of Allah is charity. Every declaration of the oneness of Allah is charity. Every exaltation of Allah is charity. Enjoining good and forbidding evil is charity. It is enough of that to perform two cycles of prayer in the forenoon.
Source: Ṣaḥīḥ Muslim 755, Grade: Sahih
Aisha reported:
كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُصَلِّي الضُّحَى أَرْبَعًا وَيَزِيدُ مَا شَاءَ اللَّهُ
The Messenger of Allah, peace and blessings be upon him, would perform forenoon prayer with four cycles and he would add more as Allah willed.
Source: Ṣaḥīḥ Muslim 719, Grade: Sahih
Umm Hani’ reported:
ذهَبْتُ إِلى رَسولِ اللَّهِ صَلّى اللهُ عَلَيْهِ وسَلَّم عامٍ الفَتْحِ فَوجدْتُه يغْتَسِلُ فَلَمَّا فَرَغَ مِنْ غُسْلِهِ صَلَّى ثَمانيَ رَكعاتٍ وَذلكَ ضُحى
I came to the Messenger of Allah, peace blessings be upon him, in the year of the liberation, and I found him performing a ritual bath. When the Prophet finished his bath, he performed eight cycles of prayer and that was in the forenoon.
Source: Ṣaḥīḥ al-Bukhārī 350, Grade: Muttafaqun Alayhi
Success comes from Allah, and Allah knows best.