Which is better: prolonging the prayer or increasing the number of rak'ahs in Al-Masjid Al-Haram and elsewhere, especially if one rak'ah therein is equivalent to one hundred thousand?

Prayer in the Sacred Mosque is better than one hundred thousand prayers in any other mosque, apart from the Prophet's Mosque. This multiplication includes both obligatory and supererogatory prayers. The minimum for an absolute supererogatory prayer is one rak'ah. So, if someone performs a voluntary prayer without intending a specific number, they may conclude it after one rak'ah or add more. This single rak'ah, in this sense, is included in the multiplication mentioned in the Hadith.