Ruling on Combining and Shortening Prayers for Military Units in the Front Lines

Q: From 'Abd al-'Aziz ibn 'Abd Allah ibn Baz, to the honorable brother, the Director of the Religious Affairs Department of the Land Forces, may Allah grant him understanding. Peace be upon you, and Allah's mercy and blessings. As for what follows:
In response to your letter requesting clarification of the Islamic ruling regarding how the members of military units stationed in the front lines should perform their prayers.

A: We inform you that if the aforementioned individuals are in their place of residence and have not traveled, they must perform the Friday prayer and complete the four-unit prayer with four units. However, if they are traveling to their station, they are not required to perform the Friday prayer, and they may shorten and combine their prayers, because the duration of their stay is unknown. May Allah guide everyone to what He loves and is pleased with. Peace be upon you, and Allah's mercy and blessings.
The General President of the Departments of Research
The General Authority for Islamic Affairs, Research and Ifta, and Guidance.