He closes the doors of his heart to everything other than God and converses with Him through the tongue of his inner faculties.
Seclusion is one dimension of privacy, while austerity is another.
The first step in privacy is completed in forty days and therefore is called undergoing a forty-day period of austerity. When the spiritual master takes the initiate into privacy, he takes him to his retiring room where he prays for him and leaves. The initiate lives an austere life in that room where he is utterly alone. In its aspect of avoiding meeting people and austerities, privacy dates back to the early days of sufism and even to the great Prophets. Numerous Prophets and saints, most particularly the glory of mankind, upon him be peace and blessings, have spent certain portions of their lives in seclusion.