Having a sutrah (screen) in front of the worshipper whilst praying is the Sunnah of the Prophet (blessings and peace of Allah be upon him). He instructed the one who is praying alone to have a sutrah in front of him so that no one will pass in front of him and interrupt his prayer. In the case of congregational prayer, if the imam has a sutrah, he is the sutrah for those who are praying behind him. In this hadith, Abu Juhayfah (may Allah be pleased with him) tells us that the Prophet (blessings and peace of Allah be upon him) set out on a journey, and they were with him. He prayed in al-Bat-ha’, which is a place outside Makkah. It is a broad watercourse in which small pebbles collect that are brought by the floodwaters. He led them in praying Zuhr and ‘Asr in shortened form, with two rak‘ahs each, and a short spear was placed in front of him to serve as a sutrah. Hence women and donkeys passed in front of him beyond the sutrah, but they did not interrupt his prayer. This hadith indicates that it is prescribed to shorten prayers when travelling..