Na rajyam na cha rajasit na dandi na cha dandikah,
dharmasauva prajasasarva rakshintasya parasparam
The closest I've found is the following verse on GRETIL:
MBh
06,012.036a na tatra rājā rājendra na daṇḍo na ca daṇḍikāḥ
06,012.036c svadharmeṇaiva dharmaṃ ca te rakṣanti parasparam