وَمِنَ ٱلَّيۡلِ فَتَهَجَّدۡ بِهِۦ نَافِلَةً۬ لَّكَ عَسَىٰٓ أَن يَبۡعَثَكَ رَبُّكَ مَقَامً۬ا مَّحۡمُودً۬ا (٧٩)
And some part of the night awake for it, a largess for thee. It may be that thy Lord will raise thee to a praised estate. (79)
Tahajjud and the Qiyam are described as a “largess” or coming with a reward. The promise of Prophet Muhammad pbuh being raised to the praised estate of Muqaam e Mahmudah. Once He is there he can ask for intercession for His Ummah who have Tawheed. (oversimplification by me, please refer to the detailed tafseer of this ayah on http://www.alhudapk.com quran tafseer)
DUA AFTER ADHAN:
Muslims make dua for him to be raised to Maqaam e Mahmudah after every adhan
Volume 1, Book 11, Number 588:
Narrated Jabir bin ‘Abdullah: Allah’s Apostle said,
“Whoever after listening to the Adhan says, ‘Allahumma Rabba hadhihi-d-da’ watit-tammati was-salatil qa’imati, ati Muhammadan al-wasilata wal-fadilata, wab’ athhu maqaman mahmudan-il-ladhi wa’ adtahu (O Allah! Lord of this perfect call (of not ascribing partners to You) and of the regular prayer which is going to be established! Kindly give Muhammad the right of intercession and superiority and send him (on the Day of Judgment) to the best and the highest place in Paradise which You promised him)’, then intercession for me will be permitted for him on the Day of Resurrection”).
Hidden in this dua in my humble opinion is a dua for our intercession on the Day of Judgement.