The Prayer of Seeking Guidance (Istikhara)
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 84
وَ رَوَى حَمَّادُ بْنُ عُثْمَانَ اَلنَّابُ عَنْهُ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: «فِي اَلاِسْتِخَارَةِ أَنْ يَسْتَخِيرَ اَللَّهَ اَلرَّجُلُ فِي آخِرِ سَجْدَةٍ مِنْ رَكْعَتَيِ اَلْفَجْرِ مِائَةَ مَرَّةٍ وَ مَرَّةً وَ يَحْمَدَ اَللَّهَ وَ يُصَلِّيَ عَلَى اَلنَّبِيِّ وَ آلِهِ ثُمَّ يَسْتَخِيرَ اَللَّهَ خَمْسِينَ مَرَّةً ثُمَّ يَحْمَدَ اَللَّهَ وَ يُصَلِّيَ عَلَى اَلنَّبِيِّ وَ آلِهِ صَلَوَاتُُ اَللَّهِ عَلَيْهِمْ وَ يُتِمَّ اَلْمِائَةَ وَ اَلْوَاحِدَةَ.
Hammad ibn Uthman al-Naab narrated from Him عليه السلام that He said: "For istikhara (seeking divine guidance), a person should seek guidance from Allah سبحانه وتعالى during the last prostration (sajdah) of the two rak'ahs of Fajr prayer by repeating it one hundred and one times, praising Allah سبحانه وتعالى, and sending blessings upon the Prophet and his family. Then, seek guidance from Allah سبحانه وتعالى fifty times, praise Allah سبحانه وتعالى again, and send blessings upon the Prophet and his family until completing the count of one hundred and one."
- Ṣaḥīḥ al-Faqīh