There are three points in this Hadith. First, the life of the Companions was simple, divested of all kinds of luxuries and comforts. They lived on whatever was available to them. Second, a man's ablution is not nullified by eating a cooked food. In the early days of Islam, this command was put into practice but later it was cancelled. Third, if a handkerchief, or a towel or water is not available, a man can (after taking a meal) clean his mouth and hands with his palms and wrists so that his clothes will not be smeared during Salat (prayer).