Definition of Aahaad Hadeeths and the obligation to act upon them
5-12-2011 | IslamWeb
Question:
1- What is the definition of Aahaad Hadeeth?
2- What is the ruling of adopting Aahaad Hadeeths as evidence and establishing rulings based on them?
3- What is the ruling of someone who denies the Sunnah with the pretext that the Quran is sufficient?
4- Please provide examples of Aahaad Hadeeths.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
The term Aahaad is the plural of Ahad, which means “one” in the Arabic language. In Hadeeth terminology, it refers to the Hadeeth that has an indication with a measure of uncertainty or a Hadeeth that reached us from one, two or more narrations but not numerous enough to make it impossible for all of the narrators to have conspired in falsehood - whether intentionally or unintentionally.
There is a lot of evidence in the Quran and Sunnah indicating the obligation of adopting Aahaad Hadeeths and using them to establish rulings. This was the methodology of the honorable Companions 
all, and those who rightly followed them.
The Companions referred to Aahaad Hadeeths and extracted rulings from them in numerous cases, and none of them objected to that. In this way they established consensus regarding the validity of using such Hadeeths.
The most famous example of Aahaad Hadeeths is the one in which the Messenger of Allaah, sallallaahu ‘alayhi wa sallam , said that deeds are judged according to the intentions behind them. The only authentic narration of this Hadeeth, as mentioned by Al-Haafith Ibn Hajar 
was transmitted on the authority of ‘Umar ibn Al-Khattaab 
. Each stage of the chain of narrators of this Hadeeth also contains only one narrator.
There is evidence in the Quran that accepting Aahaad Hadeeths is valid. Allaah The Almighty Said (what means): {And it is not for the believers to go forth [to battle] all at once. For there should separate from every division of them a group [remaining] to obtain understanding in the religion and warn their people when they return to them that they might be cautious.} [Quran 9:122] This verse refers to a small number of people, or may even refer to a single person. Had the report that was transmitted by a single person been unacceptable, Allaah The Almighty would not have encouraged a group to obtain knowledge and warn their people when they return to them. Allaah The Almighty would never encourage a futile deed.
The evidence from the Sunnah is that the Prophet, sallallaahu ‘alayhi wa sallam, sent individuals as callers to Islam to teach people in different places such as Mu‘aath ibn Jabal, Abu Moosa Al-Ash‘ari and Dihyah ibn Khaleefah Al-Kalbi . If the reports that were transmitted by individuals cannot stand as proof, this means that the Prophet, sallallaahu ‘alayhi wa sallam, sent them for no reason, and Allaah knows best.
Anyone who denies the obligation of adopting the verified authentic Sunnah, including what was said, done or approved of by the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, is an apostate, because he denies an indisputably established religious principle.
This ruling was expressly stated by Imaam As-Suyooti who used the following tradition as evidence: It was narrated on the authority of Shu‘ayb ibn Abu Fadhaalah Al-Makki that when ‘Imraan ibn Husayn mentioned the Hadeeth that proves the intercession of the Prophet, sallallaahu ‘alayhi wa sallam, on the Day of Judgment, a man denied this Hadeeth arguing that this issue was not mentioned in the Quran. Thereupon, ‘Imraan became angry and refuted that allegation by saying that the details of most religious rulings and rituals were not mentioned in the Quran but in the Sunnah, for example, the number of Rak‘ahs (units )of the daily five prayers. Then he recited the words of Allaah The Almighty (which mean): {And whatever the Messenger has given you - take; and what he has forbidden you - refrain from.} [Quran 59:7] [Al-Bayhaqi]
Finally, it is incorrect to name those who deny the Sunnah as Al-Qur’aaniyyoon (the followers of the Quran), because they are by no means followers of the Quran. Had they been so, they would not have denied what Allaah The Almighty commanded us to adopt and follow; rather they are, as described by our senior scholars, the people of misguidance who show Islam and conceal disbelief. We seek refuge in Allaah The Almighty from such people.
Allaah Knows best.