✅ Answer: Pay attention to the following narration:

1 عَنْ سَعْدٍ عَنِ الْیَقْطِینِیِّ عَنِ الْقَاسِمِ بْنِ یَحْیَی عَنْ جَدِّهِ الْحَسَنِ بْنِ رَاشِدٍ عَنْ أَبِی بَصِیرٍ وَ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِی عَبْدِ اللَّهِ علیه السلام قَالَ حَدَّثَنِی أَبِی عَنْ جَدِّی عَنْ آبَائِهِ علیهم السلام أَنَّ أَمِیرَ الْمُؤْمِنِینَ علیه السلام عَلَّمَ أَصْحَابَهُ فِی مَجْلِسٍ وَاحِدٍ أَرْبَعَمِائَةِ بَابٍ مِمَّا یَصْلُحُ لِلْمُؤْمِنِ فِی دِینِهِ وَ دُنْیَاهُ... قَالَ علیه السلام زُورُوا مَوْتَاکُمْ فَإِنَّهُمْ یَفْرَحُونَ بِزِیَارَتِکُمْ وَ لْیَطْلُبِ الرَّجُلُ حَاجَتَهُ عِنْدَ قَبْرِ أَبِیهِ وَ أُمِّهِ بَعْدَ مَا یَدْعُو لَهُمَا

📚 Al-Khisal, p. 618

Translation: Imam Sadiq, peace be upon him, said: My father narrated to me from his grandfather from his forefathers, peace be upon them, that indeed Amir al-Mu'minin, peace be upon him, in a single sitting, taught four hundred matters that are for the good of a believer in his religion and his world, until he said: Visit your dead, for indeed they are happy and pleased by your visit, and a person should ask for his need at the graveside of his father and mother after he supplicates for the two of them.

✅ In the book 📚 Al-Kafi, Vol. 3, p. 229, the above hadith is also narrated with a chain of transmission from Imam Sadiq, peace be upon him, which, however, has a minor difference from the above narration in one of its versions.

✅ It is clearly apparent that at the graveside of parents, after we supplicate for them, we ask for our need, and this place is one of the places that the Ahl al-Bayt, peace be upon them, have specifically designated for asking for a need.