Does the author mean absolute voluntary prayer in travel, or restricted voluntary prayer?

Question:
May Allah reward you. Honorable Shaykh, these are many questions; we have presented to your eminence whatever of them is feasible. This questioner says: In the statement of the author (may Allah have mercy on him), “and he would pray voluntary prayers at night and day on his mount in travel,” does he (may Allah have mercy on him) mean absolute voluntary prayer or restricted voluntary prayer?

Answer:
Absolute voluntary prayer, absolute voluntary prayer. We act upon all of it. This includes absolute voluntary prayer. Voluntary prayer at night is absolute, and voluntary prayer during the day is absolute. Yes.