Ruling on Repeating 'Umrah

What is the specified period after performing 'Umrah? If a person comes, for example, after a week, having performed 'Umrah a week ago, should he perform 'Umrah now?The Shaykh: Imam Ahmad (may Allah have mercy on him) mentioned an approximate limit. He said (may Allah have mercy on him): If the hair on his head has grown black after shaving,Meaning: then he should perform 'Umrah; because 'Umrah requires either shortening the hair or shaving it, and this cannot be completed until the hair has grown. As for what some people do today in Ramadan or during the days of Hajj, repeating 'Umrah every day, this is a religious innovation (bid'ah), and they are closer to sin than to reward. Therefore, it is obligatory for students of knowledge to clarify to these people that this is an invented matter and an innovation. They are not more eager than the Messenger of Allah (peace and blessings be upon him and his family), nor than the Companions. The Messenger of Allah (peace and blessings be upon him and his family) remained in Makkah for nineteen days during the Expedition of the Conquest and did not even think of going out to perform 'Umrah. Likewise, during the 'Umrah of Qada', he performed the 'Umrah and remained for three days without performing another 'Umrah. And the Companions (may Allah be pleased with them) did not repeat 'Umrah.