Beginningless-endless perpetuity - That permanence, which has neither beginning nor end, e.g., the perpetual shape and size of cosmos and supra-cosmos.
anādyaparyavasānanityatā sāvadhinityatā ca, tatrādyā loka-sanniveśavadanāsāditapūrvāparavadhivibhāgā santatyavyavacchedena svabhavamajahatī tirohitānekapariṇatiprasavaśaktigarbhā bhavanamātrakṛtāspadā pratītaiva
(TaBhā 5.4 Vṛ)