Islam has two primary sources. First is the Qurʾān which is the direct word of God inspired to the Prophet Muhammad peace be upon him. The second source is the Prophet’s teachings. These teachings include his words, actions, and things he approved of. The Prophet’s teachings are called Sunna. The Sunna is found in texts called ḥadīth. A ḥadīth is a statement of the Prophet peace be upon him which was narrated by his companions and subsequently narrated to the next generation until these sayings were compiled in ḥadīth collections.
The Prophet Muhammad, peace be upon him, was sent as the final messenger to mankind. With his death, the message of Islam was completed. The preservation of scripture is not limited to the text of the Qur’ān, but its meaning as well. If the Prophet’s explanation is needed in order to understand the Qur’ān, then it is necessary that his sayings be preserved as well, not only the words of the Qur’ān. In other words, without the Sunna the Quran is not preserved, what will only remain is the text without its meaning.
Imagine for instance trying to discover the manner of prayer based only the command to “establish prayer” with few references to bowing and prostration. The number of prayers, times per day, and what to recite would remain unknown. Therefore, the Sunna is part of the Qurʾān’s preservation. Without the Sunna the meaning of the Qurʾān would be lost and by extension not preserved.
Importance of Ḥadīth
All Muslims, be they Sunni or Shia, agree that ḥadīths are essential to understanding Islam. Ḥadīth are important because without them the Qurʾān does not make sense. They provide a context to the verses in the Qurʾān. The Qurʾān is a rather concise book and therefore contains many general statements. For instance, the Qurʾān commands Muslims to pray, but it does not provide the details of how one is to perform prayer.
The Qurʾān also commands Muslims to perform pilgrimage and give charity, but it does not provide the details. These details are found in the ḥadīth where the Prophet peace be upon him explained the details and mechanics of prayer. There are dozens of verses in the Qurʾān that command Muslims to follow the Prophet. Without knowing his teachings one cannot possibly fulfill this command.
Collection of Ḥadīth
The Companions of the Prophet peace be upon him memorized his statements and actions. In addition to memorization, many Companions wrote these ḥadīths down in their personal collections. These ḥadīths were passed down to the students of the Companions and subsequently down to their students. Several Muslim scholars collected these ḥadīths into compilations which have become widespread and are the main sources of ḥadīths until today.
Hadith are a Primary Source of Islamic Teachings
The verses concerning the authority of the Prophet’s teachings are abundant, for brevity we will only list four:
And Whatever the Messenger gives you, accept it, and from whatever he forbids you, abstain from it (Qurʾān 59: 7).
Say: If you love Allah then follow me and Allah will love you and forgive your sins (Q. 3: 31).
Whoever obeys the messenger has obeyed Allah (Qurʾān 4: 80).
O you who believe, obey Allah and obey the Messenger and those in authority among you. If you differ in anything, then refer it to Allah and His Messenger if you believe in Allah and the last day; that is better and the best interpretation (Qurʾān 4: 59).
The Qurʼan establishes that the Prophet, peace be upon him, must be referred to when disputations occur. This is an example of how the Prophet peace be upon him is a legislator and does not speak out of whim. The Qurʾan cannot command Muslims to follow the Prophet without making a means for them to know and follow him. If his teachings are not preserved, then the Qurʾan would be commanding Muslims to follow something that does not exist. From this we understand that part of the preservation of the Qurʾan is the preservation of the Sunna itself.
Authentication of Ḥadīth
In order to ensure that ḥadīths were authentic and not fabricated, scholars developed a unique and critical method. This consisted of two components, first scholars scrutinized the people who were narrating the ḥadīth. They ensured that everyone in the chain of transmission met each other and was free from any disqualifying characteristics. These disqualifying characteristics include lying, indulging in major sins, or having a known or obvious motive to fabricate a ḥadīth.
The second criteria they used was to measure and grade the memory of the narrations. This was done empirically by comparing the narrations of different students to see who might have made a mistake. For instance, a Companion of the Prophet might have narrated ten sayings of the Prophet to 15 students. Ḥadīth scholars would then individually ask these students to recite the ḥadīth to them. If of those 15 students 13 students say that the ḥadīth says XYZ and 2 say it says ZYX then it is likely they made a mistake. They would then note that this narrator has a poor memory and their narrations are to be rejected or accepted with caution. Hadiths would then be classified as authentic, acceptable, weak, or fabricated.
Examples of Prophet’s Statements Found in Ḥadīth
Those people who show no mercy will receive no mercy from Allah
Not one of you can (truly) believe if you do not want for your (believing) brother what you want for yourself
Do not have ill-will towards one another, do not be envious of one another, do not turn your back on one another; O, servants of Allah, be brothers (and sisters). It is not permissible for a Muslim to remain angry with their brother [in religion] for more than three days
When a human being dies all their actions and blessings come to an end, except for these three things: continuous charity, the knowledge from which they have benefited others, and a blessed child who prays for them
If someone conceals the mistake of another servant on the Day of Judgement Allah will cover their mistake
The statements of the Prophet Muhammad peace be upon him are the second source of Islamic knowledge and law. Without these statements, the Qurʾān loses its context and meaning. Scholars have developed a science which they used to determine the different levels of each ḥadīths authenticity. Ḥadīth serve as a source of guidance for Muslims in their daily lives. They use ḥadīth to learn more about the Prophet peace be upon him and try to emulate his actions and character.