Hadith 1:

محمد بن عيسى باسناده عن الصادقين عليهم السلام قال قال: وكرر في ليلة ثلاث وعشرين من شهر رمضان هذا الدعاء ساجدا وقائما وقاعدا وعلى كل حال، وفي الشهر كله، وكيف أمكنك، ومتى حضرك من دهرك تقول بعد تمجيد الله تعالى والصلاة على النبي عليه وآله السلام: (اللهم كن لوليك فلان بن فلان في هذه الساعة وفي كل ساعة وليا وحافظا وقائدا وناصرا ودليلا وعينا حتى تسكنه أرضك طوعا وتمكنه فيها طويلا).

Muhammad ibn 'Isa has narrated through the chain of his narrators that Imam Baqir (ع) / Imam Sadiq (ع) have said,

"You should repeat this prayer during the twenty-third night of the month of Ramadan, while in prostration, standing, sitting and in all conditions and during the whole month and however you can, and whenever you remember in your lifetime. After you praise Allah (تعالى), and after sending Salawat upon the Prophet (ص), You should say,

"O Allah be for Your Wali, so and so (i.e. al-Hujjah ibn al-Hasan ع) in His time and in every time, a guardian, protector, a leader, a supporter, a guide/proof and an eye until You settle him on Your earth with obedience and make Him settle in it for a long time."

[Source: Tahzeeb al-Akham, Shaikh Toosi, Vol. 3, Pg. 102]

Same Hadith with a bit of different wording is found in al-Kafi as listed below:

 مُحَمَّدُ بْنُ عِيسَى بِإِسْنَادِهِ عَنِ الصَّالِحِينَ ع قَالَ: تُكَرِّرُ فِي لَيْلَةِ ثَلَاثٍ وَ عِشْرِينَ مِنْ شَهْرِ رَمَضَانَ هَذَا الدُّعَاءَ سَاجِداً وَ قَائِماً وَ قَاعِداً وَ عَلَى كُلِّ حَالٍ وَ فِي الشَّهْرِ كُلِّهِ وَ كَيْفَ أَمْكَنَكَ وَ مَتَى حَضَرَكَ مِنْ دَهْرِكَ تَقُولُ بَعْدَ تَحْمِيدِ اللَّهِ تَبَارَكَ وَ تَعَالَى وَ الصَّلَاةِ عَلَى النَّبِيِّ ص- اللَّهُمَّ كُنْ لِوَلِيِّكَ فُلَانِ بْنِ فُلَانٍ فِي هَذِهِ السَّاعَةِ وَ فِي كُلِّ سَاعَةٍ وَلِيّاً وَ حَافِظاً وَ نَاصِراً وَ دَلِيلًا وَ قَائِداً وَ عَوْناً وَ عَيْناً حَتَّى تُسْكِنَهُ أَرْضَكَ طَوْعاً وَ تُمَتِّعَهُ فِيهَا طَوِيلًا

Muhammad ibn 'Isa has narrated through the chain of his narrators that the Imams (ع) have said,

"You should repeat this prayer during the twenty-third night of the month of Ramadan, while in prostration, standing, sitting and in all conditions and during the whole month and however you can, and whenever you remember in your lifetime. After you praise Allah (تبارك وتعالى), and after sending Salawat upon the Prophet (ص), You should say,

"O Allah be for Your Wali, so and so Imam (i.e. al-Hujjah ibn al-Hasan ع) in His time and in every time, a guardian, protector, supporter, a guide/proof, a leader, and helper (and an eye) until You settle him on Your earth with obedience and grant him comfort for a long time."

[Source: al-Kafi, Vol. 4, Pg. 162, Hadith. 4]