Is it permissible to perform a supererogatory (Nawafil) prayer after the Iqamah for the obligatory prayer has been called?
Chapter on Facing the Qiblah
Al-Mughni
Book of Prayer
Primary text
It is obligatory not to engage in any supererogatory prayer once the Iqamah for the obligatory prayer has been established, regardless of whether one fears missing the first Rak'ah or not. This position is held by Abu Hurairah, Ibn Umar, Urwah, Ibn Sirin, Sa'id ibn Jubayr, Al-Shafi'i, Ishaq, and Abu Thawr. The primary evidence is the statement of the Prophet, peace be upon him: "When the Iqamah is established, there is no prayer except the obligatory one," narrated by Muslim. Furthermore, what is missed from the congregational prayer with the Imam is superior to what one completes in a supererogatory prayer, thus one should not occupy oneself with the latter, similar to the case where one fears missing the first Rak'ah.
Supporting text
A narration attributed to Ibn Mas'ud indicates that he entered while the Imam was performing the dawn prayer and prayed the two Rak'ahs of *Sunnah* (Qabliyyah) prayer. This is the established view (Madhhab) of Al-Hasan, Mak'hul, Mujahid, and Hammad ibn Abi Sulayman. Malik stated that if one does not fear missing the Rak'ah, one may perform those two Rak'ahs outside the mosque. Al-Awza'i, Sa'id ibn Abd al-Aziz, and Abu Hanifah ruled that one may pray them unless one fears missing the final Rak'ah.