His statement, “It is permitted at all times”: Hajj, however, has a specified season. Allah the Exalted says: “Hajj is during well-known months.” [al-Baqarah 2:197] As for ‘Umrah, it may be performed at any time, though according to the well-known position of the madhhab, this is on condition that one does not enter ihram for it while already in ihram for Hajj. Hence they said: qiran is to enter Hajj into ‘Umrah, not to enter ‘Umrah into Hajj. The Shafi‘i scholars differed on this, maintaining that it is permissible to enter ‘Umrah into Hajj, thereby becoming one performing qiran.
He did not mention whether it is recommended to perform ‘Umrah at all times, once a year, or once a month.
However, Shaykh al-Islam stated in al-Fatawa that the early generations were agreed that repeatedly performing ‘Umrah is disliked.
Imam Ahmad said: “He should not perform ‘Umrah until his head has become dark [with hair].” That is, until his hair has grown back and become dark. Accordingly, what ordinary people do nowadays—repeating ‘Umrah, especially in Ramadan, every day, and some perhaps performing one ‘Umrah by day and another by night—runs contrary to the practice of the early generations.
It says in al-Rawd: “Excessively and consecutively performing ‘Umrah is disliked, by agreement of the early generations.” This was stated in al-Mubdi‘ by Ibn Muflih.
As for the Prophet’s saying, “One ‘Umrah to the next is an expiation for what lies between them” (1), its general wording is qualified by the practice of the early generations, may Allah be pleased with them.