Question:
Do you make intention (Niyyah) for 20 Raka'as Taraaweeh, at once or every Raka'as.
Fatwa:
All perfect praise be to Allah, the Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His Slave and Messenger.
The intention takes place in the heart and it is required at the start of any act of worship, as the Prophet said: “Actions are judged according to their intentions.” [Al-Bukhari and Muslim]
Therefore, whoever wants to perform Taraaweeh prayers has to have the intention of praying the Sunnah of Taraaweeh prayers. Having one absolute intention is not correct; rather, one has to have the intention for every two Rak'ahs, and having the intention at the beginning of the prayer is not enough. It is an obligation to renew the intention every two Rak'ahs.
Imaam An-Nawawi said: “Taraaweeh prayers are not valid by having only one absolute intention. Rather, one has to have the intention of the Sunnah of Taraaweeh prayers, or the prayer of Taraaweeh, or the intention of performing night prayers in Ramadan, so he has to make the intention for every two Rak'ahs of Taraaweeh prayers.”
Nonetheless, the matter is a question of a difference of opinion among the scholars . Some of them are of the view that one intention at the beginning of the prayer is enough and it is not necessary to renew the intention for each and every two Rak'ahs, because all the Taraaweeh prayers are considered as one prayer. However, what we have mentioned is more appropriate, but being keen on having the intention should not be a cause of whispers, as the intention takes place in the heart as we have previously stated and this happens automatically.
Allah Knows best.