Talhah ibn ‘Ubaydullāh (may Allah be pleased with him) informs us that they used to pray and that animals would pass in front of them. They mentioned that to the Messenger of Allah (may Allah's peace and blessings be upon him) so he told them that as long as there is something between the praying person and the passer-by, like the end of a saddle, then his passing will not harm him. Some of the benefits of the Sutrah are: maintaining the prayer, staying away from things that reduce its reward, repelling any guilt from the passer-by, and sparing him any difficulty or embarrassment.