Obligatory practices of prayer:

They are the statements and postures, which if any of them is intentionally neglected, prayer is invalidated, but if inattentively, it is not invalidated, and performing the prostration of Forgetfulness will be obligatory then.

They are eight:

1-   All the Takbeers of prayer – other than the opening Takbeer.

2-   Saying, ‘Sami’a Allaahu liman hamidah (Allaah hears those who praise Him’, which is obligatory to be said by the Imaam or the one praying alone after rising from bowing.

3-   Saying, Rabana wa laka Al-Hamd (Our Lord, praise is Yours).

4-   Saying, Subahaana Rabbiy Al-Azeem (i.e. “Glory be to my Lord, the Most Great”) only once while bowing.

5-   Saying, Subhaana Rabbiy Al-‘la” (i.e. “Glory be to my Lord, the Most High”) only once while prostrating.

6-   Invoking Allaah The Almighty saying, “O my Lord, forgive me,” once between the two prostrations.

7-   Reciting the First Tashahhud.

8-   Sitting for reciting the First Tashahhud.