Bismi Llāhi r-Raḥmāni r-Raḥīm
Do not reduce terawih prayer to 8 rakaats, do 20.
In this Sobhah, which is also translated into English, Shaykh Muhammadق speaks of the great blessings of:
1) Striving our utmost in this month to become close to Allah, this month is a priceless gift to the Ummah of Rasulullahﷺ.
2) Waking up for sahur, even if it is just to drink water
3) Doing 20 rakaats of terawih, and not 8. Doing only 8 rakaats, is a fitnah spread by shaitan to reduce the number of rakaats of terawih, to deprive believers of the great rewards of the full terawih prayers.
For thousands of years since Rasulullah’sﷺ time, and even till today at Makkah and Medina, 20 rakaats of the terawih prayer is still being done. Ignore those who try to reduce your terawih and do the full 20 rakaats nightly.
What should I do if the mosque I am praying at, does only 8 rakaats of terawih?
When you return home, do gather your family to complete the balance 12 rakaats of terawih with them. Read, short surahs.
However, you may NOT repeat the witir prayer.
Wassalam.