Explanation:

has been for or at least ten years an advocate

In order to be appointed as a Judge of the Supreme Court, a person must be a citizen of India and must have been, for atleast five years, a Judge of a High Court or of two or more such Courts in succession, or an Advocate of a High Court or of two or more such Courts in succession for at least 10 years or he must be, in the opinion of the President, a distinguished jurist. Provisions exist for the appointment of a Judge of a High Court as an Ad-hoc Judge of the Supreme Court and for retired Judges of the Supreme Court or High Courts to sit and act as Judges of that Court.