Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 85.92

85.92

yatte saṃdahyate cetaḥ śṛṇu tanme yudhiṣṭhira /
naikāpi nṛpa loke 'smin bhrūṇahatyā sudustyajā //

Hear that which burns your mind from me, O Yudhiṣṭhira: / In this world, O king, even a single slaying of an embryo is very hard to abandon;