Assalamualaikum ustaz. What is meant by the dubur (end) of prayer? The reason is I usually hear that among the places when one’s supplication is granted is at the dubur (end) of prayer. Is it after the final tasyahud or after the salam? 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.
Basically, there are several narrations that state the encouragement to supplicate at the end of prayer. Among them is from Imam al-Nasa’ie in his Sunan which placed a chapter titled “Reciting Ta’awudz at the Dubur (End) of Prayer.” He then narrated hadith al-bab from Muslim bin Abi Bakrah, he said:
كَانَ أَبِي يَقُولُ فِي دُبُرِ الصَّلاَةِ اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْكُفْرِ وَالْفَقْرِ وَعَذَابِ الْقَبْرِ فَكُنْتُ أَقُولُهُنَّ فَقَالَ أَبِي أَىْ بُنَىَّ عَمَّنْ أَخَذْتَ هَذَا قُلْتُ عَنْكَ قَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَقُولُهُنَّ فِي دُبُرِ الصَّلاَةِ
“My father used to say at the end of the prayer, “O God, I seek refuge in Thee from infidelity, poverty and the punishment in the grave.” I used to say these words also, so he asked me, “From whom did you get this, sonny?” When I told him that I had got it from him, he said that God’s messenger used to say these words at the end of the prayer.” 
Likewise, it is also based on a hadith narrated by Muaz bin Jabal where the Messenger PBUH said:
أُوصِيكَ يَا مُعَاذُ لاَ تَدَعَنَّ فِي دُبُرِ كُلِّ صَلاَةٍ تَقُولُ اللَّهُمَّ أَعِنِّي عَلَى ذِكْرِكَ وَشُكْرِكَ وَحُسْنِ عِبَادَتِكَ
“O Mu’adh, I will give you some advice – Never leave the recitation of this supplication after every prayer: ‘O Allah, help me to remember You, thank You, and worship You perfectly.'” 
Undeniably, among the times we are encouraged to supplicate for it to be granted is at the end of a prayer. This is in accordance with a hadith narrated by Abu Umamah al-Bahili RA, where Rasullullah PBUH was asked: “O Messenger of Allah, what is the most readily listened to supplication?” The Prophet PBUH then replied:
جَوْفُ اللَّيْلِ الآخِرُ وَدُبُرَ الصَّلَوَاتِ الْمَكْتُوبَاتِ
“What is offered in the latter part of the depth of the night and after the prescribed prayers.” 
According to the above hadith, Rasullullah PBUH gives guidance as to the time when supplication is readily granted are either at the depths of the night or the end of the obligatory prayer. Syeikh al-Mubarakfuri said: “Which means a supplication that is directly sent to the heavens or closest to being granted.” 
The Meaning of the word Dubur (End)
Regarding the above question, here we present several definitions of the word dubur described by Arabic linguist scholars. Among them are:
Imam Ibn Manzur said: Dubur is the antonym of the word qubul. Dubur for something is its closing (which followed it) and ending. The plural form of it is adbaar.
He cited the words of al-Jauhari which stated: Dubur is the antonym of qubul. And dubur (ending) for a month is the month’s ending. While the dubur for a house is the end or corner of the house.
Whereas Ibn Sidah said: And adbaar of prostration means the endings of a prayer. While Ibn Burzaj said: Dabir al-Amr (the ending of something) is its ending. 
Scholars’ Opinions Regarding the Meaning of Dubur (Ending) of Prayer
Scholars have differing opinions as to the meaning of the word dubur (ending) of prayer. Generally, there are two opinions on this issue:
First opinion: After the salam
Some scholars hold the opinion that the meaning of the ending of prayer is as soon as the prayer is completed. They argued presenting the statement of Allah SWT:
فَإِذَا قَضَيْتُمُ الصَّلَاةَ فَاذْكُرُوا اللَّهَ قِيَامًا وَقُعُودًا وَعَلَىٰ جُنُوبِكُمْ
“And when you have completed the prayer, remember Allah standing, sitting, or [lying] on your sides.” 
Imam al-Qurthubi in his interpretation of the above verse said: “When you have completed your prayer remember Allah with your heartbeat and tongue.” 
The above narration shows the encouragement of dhikrullah in general after prayer. Then, several hadith narrations came explaining what the dhikrs meant. Among them is through a hadith narrated from al-Mughirah bin Syu’bah RA, he said, indeed the Messenger PBUH recited the following at the end of his prayer after salam:
لاَ إِلَهَ إِلاَّ اللَّهُ، وَحْدَهُ لاَ شَرِيكَ لَهُ، لَهُ الْمُلْكُ، وَلَهُ الْحَمْدُ، وَهْوَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ، اللَّهُمَّ لاَ مَانِعَ لِمَا أَعْطَيْتَ، وَلاَ مُعْطِيَ لِمَا مَنَعْتَ، وَلاَ يَنْفَعُ ذَا الْجَدِّ مِنْكَ الْجَدُّ
“There is nothing worthy of worship except Allah Alone, Who has no partner. To Him belongs the kingdom, to Him praise is due, and He has power over everything. O Allah no one can withhold what You have given, or give what You have withheld and riches cannot avail a wealthy person against You.” 
Imam al-Bukhari in his book Sahih al-Bukhari placed this hadith in the chapter: “Supplication after prayer.”
Second opinion: After tasyahhud before salam.
Imam Ibn al-Qayyim said: “Dubur (ending) of prayer has an ihtimal (possibility) of either before or after the salam. Our teacher (Ibn Taimiyyah) concluded that it means before salam. Hence, I refer this issue to him and he said: Dubur for everything is something that is a part of it, such as the dubur od an animal.” 
They discussed this issue when commenting on the hadith:
يَا رَسُولَ اللَّهِ أَىُّ الدُّعَاءِ أَسْمَعُ قَالَ جَوْفُ اللَّيْلِ الآخِرُ وَدُبُرَ الصَّلَوَاتِ الْمَكْتُوبَاتِ
“God’s Messenger was asked which supplication is most readily listened to, and replied, “What is offered in the latter part of the depth of the night and after the prescribed prayers.” 
Thus, we say that the end of something is a part of the matter, then it can be understood that the dubur of prayer is a part of the prayer and here it means after the final tasyahhud before the salam.
In this issue, we emphasize that both these opinions should be considered and harmonized. The reason is both of them have sahih and concrete evidences.
Thus, we state that the narrations which state dhikrs and signals that it is recited after prayer, then the end of prayer means after the prayer. While for narrations which mentioned supplication at the end of the prayer and bind it with the recitation after prayer, then the end of prayer here means after the final tasyahhud and before salam.
Lastly, in terms of its practice, a person can recite supplication and dhikr at both these places, whether before salam, or even after the prayer is completed.
 Narrated by al-Nasaie (1347)
 Narrated by Abu Daud (1552)
 Narrated by al-Tirmizi (3499)
 See Tuhfah Al-Ahwazi, 9/472
 See al-Jami’ li Ahkam al-Quran, 5/319
 Narrated by al-Bukhari (6330)
 Narrated by al-Tirmizi (3499)