If someone started praying, and while he was praying, he noticed that he was in the way (e.g. he was close to an entrance) and there was pole (or anything that can be used as a sutra) in front of him, and he has to take a few steps so that the pole becomes his sutra. Is it permissible in this situation for him to walk to that pole, so that people won't commit a sin by walking in his sujood place?
Imaam Maalik said: "It is not a problem for the one who makes up some part of the prayer after the imaam finishes to move slightly to something near to him, like a pillar in front of him, or on his right or left, OR BEHIND him, he backs up towards it and takes it as a sutrah so long as it is close by. If it is far away, he remains standing (in his place), and repels those who may pass in front of him to the best of his ability."
[Sharh Az-Zarqaanee 'alaa Mukhtasir Khaleel 1/208, as found in Akhtaa' Al-Musalleen of Mash-hoor Hasan Salmaan p.87]