Answer
✅Answer: Numerous narrations allow performing acts on behalf of the deceased or dedicating good deeds to them from anywhere:
عَنْ عُمَرَ بْنِ یَزِیدَ قَالَ قَالَ أَبُو عَبْدِ اللَّهِ مَنْ عَمِلَ مِنَ الْمُؤْمِنِینَ عَنْ مَیِّتٍ عَمَلًا صَالِحاً أَضْعَفَ اللَّهُ أَجْرَهُ وَ یُنَعِّمُ بِذَلِکَ الْمَیِّتَ
📚 Wasa'il al-Shi'a (30 vols), vol.8, p.282
Translation: Imam Sadiq (peace be upon him) said: Whoever performs a righteous act on behalf of a deceased believer, Allah multiplies the reward for them and the deceased benefits from that act.
عَنْ عَلِیِّ بْنِ یَقْطِینٍ عَنْ أَبِی الْحَسَنِ مُوسَی فِی الرَّجُلِ یَتَصَدَّقُ عَنِ الْمَیِّتِ أَوْ یَصُومُ وَ یُصَلِّی وَ یُعْتِقُ قَالَ کُلُّ ذَلِکَ حَسَنٌ یَدْخُلُ مَنْفَعَتُهُ عَلَی الْمَیِّتِ
📚 Bihar al-Anwar, vol.88, p.312
Imam Kazim (peace be upon him) said regarding someone giving charity, fasting, praying, or freeing a slave on behalf of a deceased: All of these acts are good and the reward reaches the deceased.
✅It is evident that it is not necessary to perform the act at the deceased's grave; what matters is the intention to dedicate the act to them. Regarding visiting the Ahl al-Bayt (peace be upon them), narrations indicate it can be done both from a distance and by visiting their graves. For others, visiting the grave involves going there with specific etiquettes:
📚 Man La Yahduruhu al-Faqih, vol.1, p.180
عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ قَالَ قُلْتُ لِأَبِی عَبْدِ اللَّهِ الْمَوْتَی نَزُورُهُمْ قَالَ نَعَمْ قُلْتُ فَیَعْلَمُونَ بِنَا إِذَا أَتَیْنَاهُمْ فَقَالَ إِی وَ اللَّهِ إِنَّهُمْ لَیَعْلَمُونَ بِکُمْ وَ یَفْرَحُونَ بِکُمْ وَ یَسْتَأْنِسُونَ إِلَیْکُمْ
Translation: Muhammad ibn Muslim said: I asked Imam Sadiq (peace be upon him) about visiting the dead. He said: Yes. I asked: Do they become aware of our visit? He said: By Allah, they are aware and are pleased, and they feel connected to you.
Jarah asked Imam Sadiq (peace be upon him) about greeting the inhabitants of graves. He replied:
📚 Al-Kafi, vol.3, p.229
Imam Sadiq (peace be upon him) said:
السَّلَامُ عَلَی أَهْلِ الدِّیَارِ مِنَ الْمُؤْمِنِینَ وَ الْمُسْلِمِینَ رَحِمَ اللَّهُ الْمُسْتَقْدِمِینَ مِنَّا وَ الْمُسْتَأْخِرِینَ وَ إِنَّا إِنْ شَاءَ اللَّهُ بِکُمْ لَاحِقُونَ
When you enter the cemetery, say:
📚 Man La Yahduruhu al-Faqih, vol.1, pp.180-181
Translation: Sheikh Saduq reported: Imam Reza (peace be upon him) said: No servant visits the grave of a believer and recites Surah Inna Anzalnahu fi Laylat al-Qadr seven times by the grave, except that Allah forgives both the visitor and the owner of the grave.
السَّلَامُ عَلَی أَهْلِ الْجَنَّةِ
In the narration 📚 Rijal al-Kashshi, vol.2, p.836 from Imam Baqir: Whoever visits the grave of a believing brother, sits facing the Qibla, places their hand on the grave, and recites Surah Qadr seven times, will be safe from the great fear of the Day of Judgment.
مُحَمَّدُ بْنُ عَلِیِّ بْنِ الْحُسَیْنِ قَالَ قَالَ الرِّضَا (علیه السلام) : مَا مِنْ عَبْدٍ زَارَ قَبْرَ مُؤْمِنٍ فَقَرَأَ عِنْدَهُ إِنَّا أَنْزَلْنَاهُ فِی لَیْلَةِ الْقَدْرِ سَبْعَ مَرَّاتٍ إِلَّا غَفَرَ اللَّهُ لَهُ وَ لِصَاحِبِ الْقَبْرِ
Imam Baqir (peace be upon him) visited the grave of a Shi'a in Kufa, stood by the grave, prayed, and said:
📚 Al-Kafi, vol.3, p.229
✅Additionally, various visits to the Ahl al-Bayt (peace be upon them) include sending greetings to the believers as well.
فَقَالَ اللَّهُمَّ ارْحَمْ غُرْبَتَهُ وَ صِلْ وَحْدَتَهُ وَ أَسْکِنْ إِلَیْهِ مِنْ رَحْمَتِکَ مَا یَسْتَغْنِی بِهَا عَنْ رَحْمَةِ مَنْ سِوَاکَ وَ أَلْحِقْهُ بِمَنْ کَانَ یَتَوَلَّاهُ