Ramadhaan is indeed a meritorious and blessed month in which Allah made fasting obligatory and taraaweeh salaah sunnah. Taraaweeh salaah is a salient feature of Ramadhaan for which numerous rewards and virtuous have been stipulated.

Hazrat Abdur Rahman ibn Auf [radiyallahu anhu] quotes Rasoolullah as saying: “Ramadhaan is a month in which fasting has been made obligatory upon you and I have made taraaweeh salaah sunnah upon you. Whoever fasts and performs taraaweeh salaah in this month with true faith and hope for reward will emerge sinless just as the day his mother gave birth to him.” (Ibn Majah; Kanzul Ummaal)

Taraaweeh salaah which is sunnah mu’akkadah consists of twenty rakaats.
Rasoolullah; the Sahaba; the Ulama and the Auliya performed twenty rakaats of taraaweeh salaah.

Hazrat Ibn Abbaas [radiyallahu anhu] narrates that apart from the witr salaah Rasoolullah performed twenty rakaats of salaah in the month of Ramadhaan. (Baihaqi; Ibn Abi Shaibah)

Hazrat Saa’ib ibn Yazeed [radiyallahu anhu] narrates that in the time of Hazrat Umar [radiyallahu anhu] during Ramadhaan the Sahaba performed twenty rakaats of salaah in which they read approximately one hundred verses of the Quran. During the time of Hazrat Uthman [radiyallahu anhu] the Sahaba during taraaweeh salaah leaned on the staffs due to the extreme length of the salaah. (Baihaqi)

Hazrat Mohammad ibn Ka’b Al-Qurzi narrates that in the time of Hazrat Umar [radiyallahu anhu] the people performed twenty rakaats of salaah in Ramadhaan. Together with this they performed three rakaats of witr salaah.

Hazrat Yahya ibn Sa’eed narrates that Hazrat Umar [radiyallahu anhu] instructed a certain person to lead the congregation in performing the twenty rakaats of taraaweeh salaah. (Ibn Abi Shaibah)

Hazrat Hasan [radiyallahu anhu] narrates that Hazrat Umar [radiyallahu anhu] used to assemble the people so that Hazrat Ubay ibn Ka’b could lead them in performing the twenty rakaats of taraaweeh salaah.

Hazrat Abu Abdur Rahman As-Salami narrates that Hazrat Ali [radiyallahu anhu] invited the Qurrah (reciters of the Quraan) in the month of Ramadhaan and appointed one of them as their Imaam to perform the twenty rakaats of taraaweeh salaah. Hazrat Ali [radiyallahu anhu] himself performed the witr salaah for them. (Baihaqi)

Hazrat Zaid ibn Wahb narrates that Hazrat Abdullah ibn Mas’ud [radiyallahu anhu] used to lead us in performing the twenty rakaats of taraaweeh salaah. He then departed when the night was still young. Hazrat A’amash verifies that he performed twenty rakaats of salaah.

It is ascertained that Hazrat Ubay ibn Ka’b [radiyallahu anhu] led the congregation in performing twenty rakaats of taraaweeh salaah as well as the three rakaats witr salaah. Most Ulama are of the opinion that this is the sunnah method as Hazrat Ubay performed salaah in this manner in the presence of eminent Muhajireen and Ansaar and none objected to this. (Fataawa Ibn Taymiyyah)

The noble Sahaaba unanimously agreed that taraaweeh salaah consists of twenty rakaats and the Sahaba would never agree on an incorrect matter or on any such matter which contradicts the sunnah.

Allah says in the Quran: “Whoever opposes the Messenger after guidance has been made evident to him, and follows a path other than that of the believers, We will turn him away just as he turned and we will enter him in jahannam, and an evil abode it is.” In this verse a stern warning has been issued to those who oppose Rasoolullah and the true believers.

The performance of twenty rakaats of taraaweeh salaah is the consensus of those who lived in the period classified as ‘the best of times’ (i.e. the Sahaba).
Regarding the Sahaba Rasoolullah has said:

• “The best of people are those of my time, then those who are after them, then those who are after them.”
• “The example of my Sahaba in this ummah is like salt in food; without salt the food will not be correct.”
• “My Sahaba are like guiding stars; whomsoever you choose to follow you will be rightly guided.”

When the best of people from the best of times agreed that taraaweeh salaah is twenty rakaats then following them is compulsory.

Presently some ignorant people claim that taraaweeh salaah is only eight rakaats. These people regard themselves to be more understanding than the Sahaba in the laws of Islam. They openly contradict the Sahaba. Not only are they themselves deviated but they deviate others as well. They follow nothing but their vain desires.
May Allah guide them and protect us from falling into the same error. Ameen.