Skandapurana 5.203.21

5.203.21

ye punaḥ pṛṣṭhadeśe tu hanyate bhayaviklavāḥ ..
bhujyamānāḥ paraiste ca pretāḥ syustridaśādhipa .. 21 ..

Those, on the other hand, who are struck in the back, agitated by fear, / being consumed by enemies—they become ghosts, O lord of the thirty [gods]. // 21