Matsyapurana 139.2

139.2

bho 'surendrādhunā sarve nibodhadhvaṃ prabhāṣitam
yatkartavyaṃ mayā caiva yuṣmābhiśca mahābalaiḥ //

He said: “O, Asuras! Hear what I say. Realize, O, brave! What you and I ought to do now. O Dânavas with beautiful moonlike faces! the moment the Moon and the asterism Puṣyâ unite, this fort Tripurâ will come for a moment in one line with them. I wanted and got this boon for such a moment when this fort can be destroyed by Śiva with only one arrow. You should all sing fearlessly. The destruction of Tripura can only be worked out in Puṣyâ. If any Deva comes at that time arrayed in battle and can destroy these three forts with only one powerful arrow, then and then only this will fall, otherwise, this fort is indestructible. O, heroes! Now shew your war tactics, strength, enmity to the Devas and do your best to protect this Tripura with all your might and main till Puṣyâyoga occurs and gets over. If you can turn away the chariot of Śiva in such a way as He may not be able to discharge His fatal arrow, then and then only we need not fear. If we are able to guard our Tripura in this way, the Devas will, in vain, await the advent of Puṣyâ.”—2-8