Hisn al-Muslim
The excellence of asking for Allah's blessings upon the Prophet pbuh — Du'a 2
وَقَالَ صلى الله عليه وسلم: ((لاَ تَجعَلُوا قَبرِي عِيداً وَصَلُّوا عَلَيَّ؛ فَإِنَّ صَلاَتَكُم تَبلُغُنِي حَيثُ كُنتُم)).
English meaning
He (PBUH) also said: ‘Do not take my grave as a place of habitual ceremony. Send prayers upon me, for verily your prayers reach me wherever you are.