Hadithcore
Mishkat al-Masabih, 934

Abu Huraira reported God’s Messenger as saying, “If anyone invokes a blessing on me at my grave I shall hear him, and if anyone invokes a blessing on me at a distance I shall have it conveyed to me.” Baihaqi transmitted it in <i>Shu‘ab al-lman</i>.

وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنْ صَلَّى عَلَيَّ عِنْدَ قَبْرِي سَمِعْتُهُ وَمَنْ صَلَّى عَلَيَّ نَائِيًا أُبْلِغْتُهُ» . رَوَاهُ الْبَيْهَقِيُّ فِي شعب الْإِيمَان

References1 variant
In-Book Reference
Book 4, Hadith 357