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 pre-Sunnah (voluntary prayer) of Dhuhr may be performed in pairs (two-Rak’ah prayers) and may also be performed as four Rak’ahs like Dhuhr prayer.
Khash-shaf Al-Qina’, one of the Hanbali School of jurisprudence books, reads about the voluntary prayers: “Prayers in daytime and night should be performed in pairs. This means that one should perform them as two-Rak’ah prayers, reciting Tasleem after each two Rak’ahs. This is evidenced by the Hadith narrated by Ibn ‘Umar that the Prophet, sallallahu ‘alayhi wa sallam, said: “The (voluntary) day and night prayers are (performed as) two Rak’ahs, two Rak’ahs (i.e., in pairs)” … There is nothing wrong with performing four voluntary Rak’ahs during daytime, in the same manner he performs Dhuhr prayer; it is not disliked, as evidenced by the Hadith narrated on the authority of Abu Ayyoob, may Allah be pleased with him, that the Prophet, sallallahu ‘alayhi wa sallam, used to pray four Rak’ahs before Dhuhr without separating each two Rak’ahs with Tasleem. [Abu Dawood and Ibn Majah]”. [End of quote]
Scholars held different opinions regarding the obligation of reciting the Salat Al-Ibraheemiyyah (i.e., Abrahamic prayer or supplication in the Tashahhud). Some held that it is recommended to recite it and others believed that it is one of the pillars of the prayer. It should be recited during the last Tashahhud before Tasleem, in the four-Rak’ah and two-Rak’ah prayers.
For more benefit on supererogatory [Sunnah or Rawatib] prayers, please refer to Fatawa 20804, 233800, 102385, 84719, and 88390.
Allah knows best.