Skandapurana 17.19.37

17.19.37

idaṃ rahasyaṃ paramaṃ tavoktaṃ na vācyametaddharibhaktivarjite ..
dvijasya nindānirate'tipāpe gurāvabhakte kṛtapāpabuddhau .. 37 ..

This supreme secret has been spoken to you; it must not be told to one devoid of devotion to Hari,
to one devoted to reviling twice-borns, to a grave sinner, to one lacking devotion to the guru, or to one whose mind is set on sin.