Prayer: If unsure about staying 10 days at a destination, how should one pray?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: If unsure about staying 10 days at a destination, how should one pray?

English:

Question #671:

Someone travels to a place without knowing whether they are going to stay there for ten days or less, how should they say the prayers?

Answer #671:

They should shorten their prayers for thirty days then pray in full even if they want to leave on the same day.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer