✅Answer: According to numerous narrations, one thousand rak'ahs of supererogatory prayers are performed during the month of Ramadan in several ways, 300 of which are performed on the nights of the 19th, 21st, and 23rd of Ramadan, and the details are found in various narrations:

1 أَبِي خَدِيجَةَ عَنْ أَبِي عَبْدِ اللَّه قَالَ: كَانَ رَسُولُ اللَّه إِذَا جَاءَ شَهْرُ رَمَضَانَ- زَادَ فِي الصَّلَاةِ وَ أَنَا أَزِيدُ فَزِيدُوا

📚 Al-Tahdheeb, vol. 3, p. 60

Imam Sadiq, peace be upon him, said: When the month of Ramadan arrived, the Messenger of Allah, peace be upon him and his family, would increase his prayers, and I also increase, so you also increase the number of prayers (in the month of Ramadan).

✅According to the narrations, including the two following narrations, in general, the supererogatory prayers (including the supererogatory prayers of the month of Ramadan) are performed in two-rak'ah units:

2 عَلِيِّ بْنِ جَعْفَرٍ عَنْ أَخِيهِ مُوسَى بْنِ جَعْفَر قَالَ: سَأَلْتُهُ عَنِ الرَّجُلِ يُصَلِّي النَّافِلَةَ أَ يَصْلُحُ لَهُ أَنْ يُصَلِّيَ أَرْبَعَ رَكَعَاتٍ لَا يُسَلِّمُ بَيْنَهُنَّ قَالَ لَا إِلَّا أَنْ يُسَلِّمَ بَيْنَ كُلِّ رَكْعَتَيْنِ

📚 Qurb al-Isnad, p. 90

Ali ibn Ja'far said: I asked Musa ibn Ja'far, peace be upon him, about a person who performs supererogatory prayers, is it proper for him to perform four rak'ahs and not give the 'salam' in between? He said: No, unless he gives the 'salam' between every two rak'ahs.

3 أَبِي بَصِيرٍ قَالَ: قَالَ أَبُو جَعْفَرٍ فِي حَدِيثٍ وَ افْصِلْ بَيْنَ كُلِّ رَكْعَتَيْنِ مِنْ نَوَافِلِكَ بِالتَّسْلِيم

📚 Al-Sara'ir, p. 479

Imam Baqir, peace be upon him, said: Separate between every two rak'ahs of your supererogatory prayer with the giving of 'salam'.

✅In those narrations of the supererogatory prayers of the month of Ramadan where the type of surah after Al-Fatihah is specified, Surah al-Tawhid is mentioned, and in some of them, it is stated that in the supererogatory prayers of the month of Ramadan, after Al-Fatihah, Surah al-Tawhid should be recited ten times, including:

4 صَالِحِ بْنِ أَبِي حَمَّادٍ قَالَ: كَتَبْتُ إِلَى أَبِي مُحَمَّدٍ أَسْأَلُهُ عَنِ الْغُسْلِ فِي ليالي شَهْرِ رَمَضَانَ فَكَتَبَ إِنِ اسْتَطَعْتَ أَنْ تَغْتَسِلَ لَيْلَةَ سَبْعَ عَشْرَةَ- وَ لَيْلَةَ تِسْعَ عَشْرَةَ وَ لَيْلَةَ إِحْدَى وَ عِشْرِينَ- وَ لَيْلَةَ ثَلَاثٍ وَ عِشْرِينَ فَافْعَلْ فَإِنَّ فِيهَا تُرْجَى لَيْلَةُ الْقَدْرِ- فَإِنْ لَمْ تَقْدِرْ عَلَى إِحْيَائِهَا فَلَا يَفُوتُكَ إِحْيَاءُ لَيْلَةِ ثَلَاثٍ وَ عِشْرِينَ تُصَلِّي فِيهَا مِائَةَ رَكْعَةٍ تَقْرَأُ فِي كُلِّ رَكْعَةٍ الْحَمْدَ مَرَّةً وَ قُلْ هُوَ اللَّهُ أَحَدٌ عَشْرَ مَرَّاتٍ.

📚 Fada'il al-Ashhur al-Thalathah, p. 103

Salih ibn Abi Hammad said: I wrote a letter to Abu Muhammad Imam Hasan Askari, peace be upon him, and asked about the ritual bath on the nights of the month of Ramadan; the Imam wrote in response: If you can perform the ritual bath on the 17th, 19th, 21st, and 23rd nights of the month of Ramadan, do so, for on these nights the Night of Qadr is hoped for, and if you are not able to stay up for all of them, then do not miss staying up for the 23rd night, in which you should perform three hundred rak'ahs of prayer, in each rak'ah of which you recite Surah al-Fatihah once and Surah Qul Huwa Allahu Ahad ten times.

✅ But also pay attention to the following narration:

5 الْمُفَضَّلِ بْنِ عُمَرَ عَنْ أَبِي عَبْدِ اللَّه أَنَّهُ قَالَ: تُصَلِّي فِي شَهْرِ رَمَضَانَ زِيَادَةَ أَلْفِ رَكْعَةٍ.... ثُمَّ قَالَ يَا مُفَضَّلَ بْنَ عُمَرَ تَقْرَأُ فِي هَذِهِ الصَّلَوَاتِ كُلِّهَا أَعْنِي صَلَاةَ شَهْرِ رَمَضَانَ- الزِّيَادَةَ مِنْهَا بِالْحَمْدِ وَ قُلْ هُوَ اللَّهُ أَحَدٌ- إِنْ شِئْتَ مَرَّةً وَ إِنْ شِئْتَ ثَلَاثاً وَ إِنْ شِئْتَ خَمْساً وَ إِنْ شِئْتَ سَبْعاً وَ إِنْ شِئْتَ عَشْراً

📚 Al-Tahdheeb, vol. 3, p. 66

Imam Sadiq, peace be upon him, said in a hadith: In the month of Ramadan, increase your prayers by one thousand rak'ahs... until he said: O Mufaddal, in all the supererogatory prayers of the month of Ramadan (i.e., this added one thousand rak'ahs in the month of Ramadan), recite Surah al-Fatihah (once) and Qul Huwa Allahu Ahad, if you wish, once, and if you wish, three times, and if you wish, five times, and if you wish, seven times, and if you wish, ten times.

✅Based on the above narration, in the supererogatory prayers specific to the month of Ramadan, we can recite Surah al-Tawhid 7, or 5, or 3, or once in each rak'ah after Al-Fatihah, instead of ten times.

✅In the hadith of 📚 Tahdheeb, vol. 3, p. 67, and elsewhere, Imam Baqir, peace be upon him, in the hadith of mentioning the supererogatory prayers specific to the month of Ramadan, said, among other things:

وَ ذَلِكَ سِوَى الْخَمْسِينَ

Meaning: These supererogatory prayers of the month of Ramadan are separate from the fifty rak'ah prayer (i.e., 17 rak'ahs of obligatory prayer and 33 or 34 rak'ahs of daily and perpetual supererogatory prayer).

✅The general public refers to the supererogatory prayers of the month of Ramadan as the 'Tarawih' prayer and performs it in congregation, while congregational prayer in these prayers is a certain innovation of the general public.