✅Answer:

1 مُحَمَّدِ بْنِ عُمَرَ بْنِ يَزِيدَ قَالَ: قُلْتُ لِأَبِي عَبْدِ اللَّهِ يُصَلَّى عَنِ الْمَيِّتِ فَقَالَ نَعَمْ حَتَّى إِنَّهُ يَكُونُ فِي ضِيقٍ فَيُوَسَّعُ عَلَيْهِ ذَلِكَ الضِّيقُ ثُمَّ يُؤْتَى فَيُقَالُ لَهُ خُفِّفَ عَنْكَ هَذَا الضِّيقُ بِصَلَاةِ فُلَانٍ أَخِيكَ

📚Al-Bihar, Vol. 88, p. 3

Muhammad ibn Umar ibn Yazid said: 'I said to Imam Sadiq (peace be upon him): 'Is prayer offered on behalf of the deceased?' He said: 'Yes, to the extent that a deceased person may be in distress, and that distress is alleviated for him, then it is said to him: 'This distress has been relieved for you because of the prayer of your such-and-such brother.'

2 عَنْ هِشَامِ بْنِ سَالِمٍ فِي أَصْلِهِ وَ هُوَ مِنْ رِجَالِ الصَّادِقِ وَ الْكَاظِمِ قَالَ هِشَامٌ فِي كِتَابِهِ وَ عَنْهُ قَالَ: قُلْتُ لَهُ يَصِلُ إِلَى الْمَيِّتِ الدُّعَاءُ وَ الصَّدَقَةُ وَ الصَّوْمُ وَ نَحْوُهَا قَالَ نَعَمْ قُلْتُ أَ وَ يَعْلَمُ مَنْ يَصْنَعُ ذَلِكَ بِهِ قَالَ نَعَمْ ثُمَّ قَالَ يَكُونُ مَسْخُوطاً عَلَيْهِ فَيُرْضَى عَنْهُ

📚Al-Bihar, Vol. 88, p. 310

Hisham said: 'I said to the Imam (peace be upon him): 'Do supplication, charity, fasting, and the like reach the deceased?' He said: 'Yes.' I said: 'Does he know who has done it?' He said: 'Yes, and he may be in a state of anger, and then becomes pleased.'

3 عَنْ عَلِيِّ بْنِ أَبِي حَمْزَةَ قَالَ: قُلْتُ لِأَبِي إِبْرَاهِيمَ أَحُجُّ وَ أُصَلِّي وَ أَتَصَدَّقُ عَنِ الْأَحْيَاءِ وَ الْأَمْوَاتِ مِنْ قَرَابَتِي وَ أَصْحَابِي قَالَ نَعَمْ تَصَدَّقْ عَنْهُ وَ صَلِّ عَنْهُ وَ لَكَ أَجْرٌ بِصِلَتِكَ إِيَّاهُ.

📚 Al-Bihar, Vol. 88, p. 310

Ali ibn Abi Hamza said: 'I said to Imam Kazim (peace be upon him): 'I perform Hajj and I pray and I give charity on behalf of my living and deceased relatives and friends.' He said: 'Yes, give charity on his behalf and pray, and you will also have a reward for maintaining ties with him.'

4 عَنْ عَلِيِّ بْنِ يَقْطِينٍ عَنْ أَبِي الْحَسَنِ مُوسَى فِي الرَّجُلِ يَتَصَدَّقُ عَنِ الْمَيِّتِ أَوْ يَصُومُ وَ يُصَلِّي وَ يُعْتِقُ قَالَ كُلُّ ذَلِكَ حَسَنٌ يَدْخُلُ مَنْفَعَتُهُ عَلَى الْمَيِّتِ.

📚Al-Bihar, Vol. 88, p. 312

Imam Kazim (peace be upon him) said about a person who gives charity, fasts, prays, or frees a slave on behalf of a deceased person: 'All of these are good, and their benefit reaches the deceased.'

5 قَالَ: قَالَ أَبُو عَبْدِ اللَّه إِنَّ الصَّلَاةَ وَ الصَّوْمَ وَ الصَّدَقَةَ وَ الْحَجَّ وَ الْعُمْرَةَ وَ كُلَّ عَمَلٍ صَالِحٍ يَنْفَعُ الْمَيِّتَ حَتَّى إِنَّ الْمَيِّتَ لَيَكُونُ فِي ضِيقٍ فَيُوَسَّعُ عَلَيْهِ وَ يُقَالُ هَذَا بِعَمَلِ ابْنِكَ فُلَانٍ وَ بِعَمَلِ أَخِيكَ فُلَانٍ أَخُوكَ فِي الدِّينِ.

📚Al-Bihar, Vol. 88, p. 313

Imam Sadiq (peace be upon him) said: 'Indeed, prayer, fasting, charity, Hajj, Umrah, and any righteous deed benefit the deceased to the extent that he may be in distress, and then his distress is alleviated, and it is said to him: 'This is due to the deed of your son or due to the deed of your such-and-such religious brother.'

6 قَالَ أَبُو عَبْدِ اللَّه مَنْ عَمِلَ مِنَ الْمُؤْمِنِينَ عَنْ مَيِّتٍ عَمَلًا أَضْعَفَ اللَّهُ لَهُ أَجْرَهُ وَ يُنَعِّمُ بِهِ الْمَيِّتَ

📚Al-Bihar, Vol. 88, p. 314

Imam Sadiq (peace be upon him) said: 'Whoever among the believers performs a deed on behalf of a deceased person, Allah will multiply his reward and will also make the deceased benefit and enjoy it.'

7 قَالَ وَ قَالَ إِنَّ الْمَيِّتَ لَيَفْرَحُ بِالتَّرَحُّمِ عَلَيْهِ وَ الِاسْتِغْفَارِ لَهُ كَمَا يَفْرَحُ الْحَيُّ بِالْهَدِيَّةِ تُهْدَى إِلَيْهِ.

Al-Faqih, Vol. 1, p. 183

The Messenger of Allah (peace be upon him) said: 'Indeed, the deceased person rejoices and is gladdened by mercy and seeking forgiveness for him, just as a living person is gladdened by a gift given to him.'

✅In many narrations, the permissibility, effectiveness, and the deceased's rejoicing from performing a righteous deed and sending and gifting its reward to the deceased have been transmitted. According to the narrations in 📚Kafi, Vol. 3, p. 239, the deceased, according to their level of virtue, visit their families and become aware of some of their circumstances. However, we have refrained from transmitting the popular belief about the specific expectation of the deceased on Friday because it has not been narrated through a reliable Shia source. But we can perform any righteous deed on behalf of the deceased at all times and gift it to them, as according to the above narrations, their distress will be alleviated and they will be gladdened.