Like the three-fold objects of life beginning with Religion, or the three-fold sacred fires, there is a triple aggregate of everlasting Heavens, depending upon the son, the grandson, and the great-grandson.
धर्माद्या हि यथा त्रेता वह्निनेता तथैव च। तथैव पुत्रपौत्राणां स्वर्गस्त्रेता किलाक्षयः॥