The Prophet ﷺ said,
مَنْ صَلَّى عَلَىَّ صَلاَةً وَاحِدَةً صَلَّى اللهُ عَلَيْهِ عَشْرَ صَلَوَاتٍ وَحُطَّتْ عَنْهُ عَشْرُ خَطِيئَاتٍ وَرُفِعَتْ لَهُ عَشْرُ دَرَجَاتٍ
“Whoever sends blessings upon me once, Allāḥ will send blessings upon him tenfold, and will erase ten sins from him, and will raise him ten degrees in status.
[Ibn Mājah and others]
One blessing and mercy from Allāh is sufficient for the whole creation, let alone ten of Allāh’s blessings in return for invoking blessings once. What virtue for invoking blessings is there which is greater than being granted ten blessings for invoking once?
In Zād al-Saʿīd, it is narrated from Al-Mawāhib al-Ladunniyya that on the Day of Judgement, a certain believer will have fewer good deeds. The Prophet ﷺ will place a parchment the size of a fingertip on the Scales. The pan of good deeds will become heavy.
The believer will say, “May my parents be sacrificed for your sake. Who are you? How beautiful your appearance and character are!”
The Prophet ﷺ will reply, “I am your Prophet and these are the blessings you invoked upon me. I have recompensed you in your time of need.”
One should not doubt that a parchment the size of a fingertip can weigh down the Scales, because it is sincerity which is of value to Allāh. The more sincerity in an action, the more it shall weigh.
[Virtues of invoking blessings and peace on the Noble Prophet ﷺ, Sheikh-ul-Ḥadīth Mawlāna Muḥammad Zakariyyā Kāndhalawī رحمه الله, Page 18, 38]
اللهم صل على محمد و على آل محمد كما صليت على إبراهيم و على آل إبراهيم إنك حميد مجيد، اللهم بارك على محمد و على آل محمد كما باركت على إبراهيم و على آل إبراهيم إنك حميد مجيد