Is it permissible to combine the intention of the regular Sunnah prayer and "reviving what is between the two 'Ishas" (i.e., praying between Maghrib and 'Isha) in two rak'ahs after Maghrib, and to combine the intention of the regular Sunnah prayer, the night prayer (qiyam al-layl), the even-numbered prayer (shaf') for Witr, and the Istikhara prayer in two rak'ahs after 'Isha?

There is no objection to performing the ratibah (supererogatory prayer) of Maghrib with the intention of it being the ratibah and also to revive the time between the two 'Ishas, because reviving this time generally occurs through acts of obedience such as prayer, reciting the Qur'an, and dhikr (remembrance of Allah). Jurists have differed regarding the number of rak'ahs for reviving the time between the two 'Ishas; some said six rak'ahs, while others said two rak'ahs or more.

It is not permissible to combine the intention of the ratibah of 'Isha with the two rak'ahs of shaf' (even-numbered prayer) because each of them is intended for its own sake.

However, combining the intention of the ratibah of 'Isha with qiyam al-layl (night prayer) is permissible, because qiyam al-layl is achieved by performing supererogatory prayers after 'Isha, even if it is its ratibah.

It is permissible to combine the ratibah of 'Isha with Istikhara (prayer for guidance), and one should make the Istikhara supplication after the taslim (salutation of peace) from the ratibah, because Istikhara is not intended for its own sake; rather, what is intended is the occurrence of the supplication after a prayer.