He—may Allah have mercy on him—was also asked:

A man has many missed prayers to make up. Should he offer their accompanying sunnah prayers as well, or only the obligatory prayers? May they be made up at any time of night or day?

He replied:

Hastening to make up many missed prayers takes precedence over occupying oneself with voluntary prayers instead. If, however, only a few prayers have been missed, it is good to make up their accompanying sunnah prayers as well. When the Prophet, peace and blessings be upon him, and his Companions slept through the Fajr prayer in the year of Hunayn, they made up both the sunnah and the obligatory prayer. When he missed prayers on the day of the Battle of the Trench, however, he made up the obligatory prayers without their accompanying sunnah prayers.

Missed obligatory prayers may be made up at any time, for the Prophet, peace and blessings be upon him, said:

“Whoever performs one rak‘ah of Fajr before the sun rises should pray another to complete it.”

And Allah knows best.

He was also asked:

Which is better: offering voluntary prayers or making up missed prayers?

He replied:

If someone is obliged to make up missed prayers, attending to them takes precedence over offering voluntary prayers that distract him from doing so.