A type of Pariṣaha (hardship);
the ascetic (Muni) should overcome the despondency (or disbelief) that may be created due to the failure in attaining the supersensory perception of the subtle categories.
natthi nūṇaṃ pare loe iḍḍhī vāvi tavassiṇo.
aduvā vaṃcio mi tti ii bhikkhū na ciṃtae...
abhū jiṇā atthi jiṇā, aduvāvi bhavissai.
musaṃ te evamāhaṃsu, ii bhikkhū na ciṃtae...
(U 2.44,45)