There are many narrations that show the virtue of the Ziyarat of Imam al-Hussayn (peace be upon him) in this blessed night, as the reward of the Ziyarat of Imam al-Hussayn (peace be upon him) either from near or afar is indescribable, noting that there are specified Ziyarat texts for this special time, the Ziyarat of the eve of mid Sha'ban. Some of these narrations are as follows:
It is narrated from Imam As-Sadeq (peace be upon him) that he said: "Imam Al-Baqer (peace be upon him) was asked about the merit of the eve of the mid Sha'ban, and he (peace be upon him) said: "The most virtuous night after Laylat-ul Qadr is that of the 15th of Sha’ban, and Allah grants His blessings, during this night, to His servants and forgives them by means of His grace and greatness; hence, endeavor during this night with the intention to gain proximity to Almighty Allah. (Note that) Allah has sworn that He does not deprive any ‘beggar’ (one who earnestly requests/begs from Him) – unless the latter requests and searches for something sinful or unpleasant. This night is one which Almighty Allah has bestowed upon us, the Ahl Al-Bayt, as Laylat al-Qadr was granted to the Holy Prophet."
One of the recommended and desirable acts during this night is the Ziyarat of Imam Al-Hussayn (peace be upon him), as it was narrated that Imam As-Sadeq (peace be upon him) said: "The sins of the visitor of Al-Hussayn Ibn Ali on the fifteenth of Sha'ban are forgiven, and no sin is written in his book for a year, and if he visits the next year, God will forgive his sins." And Imam As-Sadeq (peace be upon him) also said: "He who visits Aba Abdillah Al-Hussayn (peace be upon him) three years in row without intersection on the fifteenth of Sha'ban, his sins will be forgiven," He (peace be upon him) also said: "When it is the fifteenth of Sha'ban, a caller from beyond the horizon says to the visitors of Al-Hussayn: Return, forgiven and your reward is on Allah your Lord and Mohammad."
Imam Ali as-Sajjad (peace be upon him) said that if someone wishes to meet the souls of the One Hundred Twenty Four Thousand Prophets, he/she should perform the Ziyarat of Imam al-Hussayn (peace be upon him) during this night.
On the night of the 15th Sha'ban, the night of the birth of Imam al-Mahdi (may Allah hasten his holy reappearance), one of the best deeds is to recite Ziyarat of Imam al-Hussayn (peace be upon him). Sheikh Abbas al-Qummi in his Mafatih al-Jinan, says that there are many authentic hadiths regarding the rewards for those who visit Imam al-Hussayn (peace be upon him) in the middle of Sha'ban; it is as if the visitor shook hands with the 124,000 prophets.
Renewing one's allegiance to Imam al-Hussayn (peace be upon him) is renewing one's allegiance to Imam al-Mahdi (may Allah hasten his holy reappearance). Without having love for Imam al-Hussayn (peace be upon him), you are not counted as a lover of Imam al-Mahdi (may Allah hasten his holy reappearance).
This night takes its honor, holiness and sanctity from the birth of the great savior, the promised hope, the aspired good, the interpreter of the Quran, the Imam of humans and Jinns, the Master of the Advent, the Imam of the Order, our Master the awaited Al-Mahdi Son of Al-Hassan (may our souls and the souls of both worlds be a redemption for the soil of his arrival) on the Sahar time in the year 255 AH in Samarra.
And in order to revive this night, the recommended acts are:
1- It is advisable to stay awake during this full night in prayer as it has many rewards, hadith has confirmed that as for one who spends this whole night with acts of worship, his heart will not die when other hearts die.
2- Take Ghusl (Bath) with the thought of washing away sins & as if it’s your last Ghusl.
3- Imam Ja’far son of Mohammad as-Sadiq (peace be upon him) had advised the faithfuls to pray a 2 Raka’t tonight, after Isha prayers, as under: In the first Raka’t recite Surat al-Fatihah and Surat al-Kafiroon. In the second Raka’t recite Surat al-Fatihah and Surat al-Ikhlas. After the Salam recite `subhanallah’ thirty-three times, ‘alhamdulillah’ thirty-three times, and ‘allahu-akbar’ thirty-four times and then following Dua’a: "O He to whom the bondmen turn to in the event of urgent important matters; and unto whom run for help the people when the misfortune strikes!...[see Mafatih al-Jinan for the dua and the detailed description of this prayer].
4- Recite the Ziyarat of Imam al-Hussayn (peace be upon him) for 15th of Sha'ban as all the Prophets & Angels visit the Imam on this night.
As a short salutation, one may go to the terrace/elevated place, look left, right & towards the sky & recite:- Assalamu Alalika Ya Aba Abdillah Assalamu Alaikum wa Rahmatullah e wabarakatoh
السَّلامُ عَلَيْكَ يَا أَبَا عَبْدِ اللّه السَّلامُ عَلَيْكَ وَرَحْمَةُ اللّه وَبَرَكَاتُهُ
Peace be upon you; O Aba-`Abdullah! Peace and Allah’s mercy and blessings be upon you.
5- Recite Dua Kumayl for Seeking forgiveness. In Hadith, it is mentioned that Kumayl ibn Ziyad said, "I was sitting with my master Amir al-Mominin ‘Ali ibn Abu Talib (peace be upon him) in Masjid Kufa and a group of companions were also sitting with him. One of them asked him what the meaning of the verse 'Whereupon every wise command is made clear.' (Surah ad-Dukhan, Verse 4) The Imam (peace be upon him) replied, The meaning of this is the night of the 15th of Sha‘ban. I swear by the One who holds the life of ‘Ali in His hands there is not a single servant of Allah except that all the good and bad that will reach him in this year is divided up and handed out on the 15th of Sha‘ban and this good and bad will continue from the 15th of Sha‘ban until the next year on the same night. The servant who stays up this night and recites the Du‘a of Khidr will have his supplications answered." This dua taught to Kumayl ibn Ziyad is now known popularly as Dua Kumayl.
6- Recite the Salawat narrated by Imam as-Sajjad (peace be upon him). ...