CC Antya 6.309
raghunāthera niyama, — yena pāṣāṇera rekhā
Who could list the unlimited transcendental attributes of Raghunātha dāsa? His strict regulative principles were exactly like lines on a stone.
The words pāṣāṇera rekhā are very significant. Raghunātha dāsa Gosvāmī followed the regulative principles so strictly and rigidly that they were compared to the lines on a stone. As such lines cannot be erased at any time, so the regulative principles observed by Śrī Raghunātha dāsa Gosvāmī could not be changed under any circumstances.