Doubling the reward for prayer in the two Sacred Mosques for obligatory and voluntary prayers

Question:
Is the multiplication of reward in prayer in the two Sacred Mosques specific to the obligatory prayer, or does it also apply to voluntary prayers? Because the Messenger of Allah (peace and blessings be upon him) recommended voluntary prayer in the House, even though a mosque is present.

Answer:
It appears that it is for the obligatory prayer, for the intention of the obligatory prayer. However, it is known that prayer in the Haram is multiplied, and good deeds in the Haram are multiplied, even those that are not obligatory, including voluntary prayers. But the specific multiplication of one hundred thousand prayers, as in al-Masjid al-Haram, or one thousand prayers, as in al-Masjid al-Nabawi, or five hundred prayers, as in al-Masjid al-Aqsa, is, and Allah knows best, for the obligatory prayers. And voluntary prayers are multiplied because a good deed is multiplied in the Haram and in the noble places.