Assalamualaikum ustaz. When we performed the istikharah prayer, is there a condition saying then we’ll dream of the answer to the choice for the istikharah that we performed? Hope for an explanation.
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
Istikahrah is one of the ways to ask for guidance and the best route in anything that we are facing. It is one of the sunnah that was taught by the Prophet PBUH to his ummah. Allah SWT encourages His slaves to ask for His guidance in determining the choices that he has. Allah SWT states:
وَاستَعِينُواْ بِالصَّبرِ وَالصَّلَوةِ
“And seek help through patience and prayer,” 
The origin of the word istikharah comes from the word ‘خير’ which means good. The addition of the letter Alif, Sin and Ta’ gives additional meaning to it. The word ‘استخار’ means asking for a choice. This is stated by Ibn Manzur. 
Istikharah according to the fiqh terminology means asking Allah SWT to be guided and choose the best matter. This is stated by al-Dimyati: “Asking for good from something that one wants to do.”  This is also as stated by Imam Badruddin al-‘Aini, where the meaning of istikharah is said to be asking for good. 
While Al-Hafiz Ibn Hajar al-Asqalani explains istikahrah as:
طَلَبُ خَيْرِ الْأَمْرَيْنِ لِمَنَ احْتَاجَ إِلَى أَحَدِهِمَا
“Asking for guidance to choose the best from two matters for whoever wants one of them.” 
A clearer explanation from Syeikh Syams al-Haq ‘Azim Abadi stated that istikharah itself it is asking to be eased and given the better in two matters of good. Whether it is to be done or left. 
This means that istikharah prayer is performed for permissible matters and not prohibited matters. How would there be any good in something that has been prohibited by Allah SWT? This is clearly seen in the part of the istikharah supplication taught by the Prophet PBUH:
اللَّهُمَّ إِنْ كُنْتَ تَعْلَمُ أَنَّ هَذَا الأَمْرَ خَيْرٌ لِي فِي دِينِي وَمَعِيشَتِي وَعَاقِبَةِ أَمْرِي ، أَوْ قَالَ : فِي عَاجِلِ أَمْرِي وَآجِلِهِ ، فَيَسِّرْهُ لِي ، ثُمَّ بَارِكْ لِي فِيهِ
“O Allah! If you know that this matter is good for me in my religion or my livelihood, and for my life in the Hereafter – or he said: for my present and future – then make it easy for me, then bless me in it.”
Syeikh ‘Abd al-Rahman al-Mubarakfuri when commenting on this hadith said istikharah prayer its supplication is sunnah for matters when one doesn’t know which is true. As for if the good is already known such as worship and good deeds and prohibited matter, then there isn’t a need to perform istikharah prayer for it. 
Regarding istikharah prayer is among the sunnah taught by Prophet PBUH. This is based on a narration from Jabir bin Abdillah RA:
كَانَ رَسُولُ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُعَلِّمُنَا الاِسْتِخَارَةَ فِي الأُمُورِ كُلِّهَا كَمَا يُعَلِّمُنَا السُّورَةَ مِنَ القُرْآنِ ، يَقُولُ : إِذَا هَمَّ أَحَدُكُمْ بِالأَمْرِ فَلْيَرْكَعْ رَكْعَتَيْنِ مِنْ غَيْرِ الفَرِيضَةِ ، ثُمَّ لِيَقُلْ : اللَّهُمَّ إِنِّي أَسْتَخِيرُكَ بِعِلْمِكَ ، وَأَسْتَقْدِرُكَ بِقُدْرَتِكَ ، وَأَسْأَلُكَ مِنْ فَضْلِكَ العَظِيمِ ، فَإِنَّكَ تَقْدِرُ وَلاَ أَقْدِرُ ، وَتَعْلَمُ وَلاَ أَعْلَمُ ، وَأَنْتَ عَلاَّمُ الغُيُوبِ ، اللَّهُمَّ إِنْ كُنْتَ تَعْلَمُ أَنَّ هَذَا الأَمْرَ خَيْرٌ لِي فِي دِينِي وَمَعِيشَتِي وَعَاقِبَةِ أَمْرِي ، أَوْ قَالَ : فِي عَاجِلِ أَمْرِي وَآجِلِهِ ، فَيَسِّرْهُ لِي ، ثُمَّ بَارِكْ لِي فِيهِ ، وَإِنْ كُنْتَ تَعْلَمُ أَنَّ هَذَا الأَمْرَ شَرٌّ لِي فِي دِينِي وَمَعِيشَتِي وَعَاقِبَةِ أَمْرِي ، أَوْ قَالَ : فِي عَاجِلِ أَمْرِي وَآجِلِهِ ، فَاصْرِفْهُ عَنِّي ، وَاصْرِفْنِي عَنْهُ ، وَاقْدُرْ لِي الخَيْرَ حَيْثُ كَانَ ، ثُمَّ أَرْضِنِي بِهِ ، قَالَ : وَيُسَمِّي حَاجَتَهُ.
“Allah’s Messenger would teach us Al-Isthikhara for all of our affairs just as he would teach us a Surah of the Qur’an, saying: ‘When one of you is worried about a matter, then let him perform two Rak’ah other than the obligatory (prayer), then let him say: ‘O Allah! I consult Your knowledge, and seek ability from Your power, and I ask You from Your magnificent bounty, for indeed You have power and I do not have power, and You know while I do not know, and You know the unseen. O Allah! If you know that this matter is good for me in my religion or my livelihood, and for my life in the Hereafter – or he said: for my present and future – then make it easy for me, then bless me in it. If You know that this matter is bad for me in my religion and my livelihood and my life in the Hereafter – or he said: for my present and future – then divert it from me and divert me from it, enable me to find the good wherever it is, then make me pleased with it. “He said: “And he mentions his need.” 
Syeikh ‘Abd al-Rahman al-Mubarakfuri stated that what is meant by istikharah in this hadith is istikahrah prayer. He further said that this hadith is evidence that it is impermissible for a person to take anything lightly even if it is seen as insignificant. Then he leaves istikharah. There is a possibility that what he thought was insignificant may harm him in the future. 
This means that istikharah prayer is one of the ways to ask for guidance and the best route in facing anything in life. It is one of the sunnah taught by the Prophet PBUH to his ummah.
The ruling for istikharah prayer is sunnah. For those who have a need or want to ask for guidance regarding a matter that he wants to do, then it is sunnah for him to perform two rakaat and supplicate with the supplication taught by the Prophet PBUH as mentioned in the hadith narrated by Jabir. So much so that al-Aini in Umdah al-Qari stated that if one wants to choose the shoelace of his shoes, then he should ask for guidance from Allah through istikharah prayer.
Is it conditioned for a dream to determine the choice in istikharah?
First and foremost, it should be reminded that istikharah is not performed to choose between obedience or transgression, permissible and prohibited, afdhal and less afdhal, however, it is to choose between two difficult matters due to its great standing and goodness. When a person performs istikharah, then Allah SWT grant him taufiq and hidayah to perform and complete his matters the best way.
However, it has been a custom in our society to believe that the answer for istikharah must be in the form of a dream when he sleeps. This is claimed by various parties that when they saw one of their choices in a dream, they’ll choose according to the dream. However, in truth, there isn’t any syarak evidence that conditioned the answer must be in the form of only a dream.
Moreover, scholars stated that among the guidance granted by Allah SWT to those who performed istikharah is that his heart feels easy in making his decision. This is stated by Imam al-Nawawi in his book al-Adzkar saying:
وَإِذَا اسْتَخَارَ مَضَى بَعْدَهَا لِمَا يَنْشَرِحُ لَهُ صَدْرُهُ ، والله أعلم
“And when a person has performed istikharah, then he should do what he feels easier to choose in making his decision. Wallahu a’lam.” 
Likewise, Imam al-Nawawi stated in the book al-Majmu’ Syarh al-Muhazzab, stating:
ثمَّ يَنْهَض بَعْد الاسْتِخَارَة لِمَا يَنْشَرِحُ لَهُ صَدْرُهُ
“Then he should get up from the istikharah he performed and decide on the matter that his heart is easy with.” 
However, if he is still uncertain and felt uneasy or doubtful about making a decision, then he should repeat his istikharah until his heart is eased to make a choice. If he is still in the same state of unease, then if he can postpone making his choice, he should postpone it. However, if it cannot be delayed, then he should choose the one that he feels better about.
This is stated by Ibn ‘Allan, he said: if he is still anxious about making a choice, then what is clear to us is he should repeat his istikharah by performing the prayer and supplicating again until his heart is lightened.
However, if he is still anxious after repeating his prayer, if it is possible for him to postpone his decision, then he should postpone it. If this isn’t possible, then he should choose one that is easier for him, indeed, it is a sign of the will of Allah SWT and goodness.” 
According to the above evidences and statements, we state that it isn’t conditioned for the answer of istikharah performed to be in a dream, rather it doesn’t need any signs except one’s heart is lightened and the affairs are eased.
Hence, when someone has performed istikharah he should continue his matters as usual according to what he feels better and eased, and not wait for an answer in the form of a dream and others. The reason is istikharah performed is for us to ask for a good ending from Allah SWT for what we have done.
Indeed, a person who performed istikharah and istisyarah will never regret or be disappointed in Allah SWT according to a hadith where Rasullullah PBUH said:
مَا خَابَ مَنِ اسْتَخَارَ وَلَا نَدِمَ مَنِ اسْتَشَارَ وَلَا عَالَ مَن اقتَصَد
“A person who performed istikharah will never regret and a person who asked for advice will never be disappointed and a modest person will never be poor.” 
 Surah al-Baqarah: 45
 See Lisan al-Arab, 4/264
 See I’anah al-Talibin, 1/297
 See ‘Umdah al-Qari, 23/11
 See Fath al-Bari, 11/183
 See ‘Aun al-Ma’bud, 25/448
 See Tuhfah al-Ahwazi, 2/591
 Narrated by al-Tirmizi (480) and Ibn Majah (1383). Imam al-Tirmizi stated the status of this hadith is hasan sahih gharib.
 See Tuhfah al-Ahwazi, 2/482
 See al-Azkar al-Nawawiyyah, 2/241
 See al-Majmu’ Syarh al-Muhazzab, 3/546
 See al-Futuhat al-Rabbaniyyah, 2/241
 Narrated by al-Tabrani (6/365)