SAUNDARANANDA 15.13: Brightness vs Darkness

pratipakShas tayor jNeyo
maitrii kaaruNyam eva ca
virodho hi tayor nityaM
prakaasha-tamasor iva

- - = = - = = =
= = = = - = - -
- = = - - = = =
- = - - - = - -

15.13
Know their opposite

To be love and compassion;

For this opposition is forever

Like brightness and darkness.

NO DUST OR FLUFF:
Whereabouts is brightness/clarity?
Whereabouts is darkness?
What is the relationship between brightness/clarity and a jewel?
What is the relationship between darkness and turbid water?
When brightness opposes darkness, what happens to turbid water?

EH Johnston:
Know their counteragents to be benevolence and compassion ; for there is ever an opposition between them as between light and darkness.

Linda Covill:
It's known that loving-kindness and compassion are their opposite, for they are always incompatible, like light and dark.

VOCABULARY:
pratipakShaH (nom. sg.): m. the opposite side , hostile party , opposition; an obstacle ; an adversary , opponent , foe
tayoH (gen. dual): of them, of those two
jNeyaH (nom. sg. m. gerundive of jNaa): to be known

maitrii (nom. sg.): f. friendship , friendliness , benevolence , good will (one of the 4 perfect states with Buddhists)
kaaruNyam (nom. sg.): n. compassion , kindness
eva: emphatic
ca: and

virodhaH (nom. sg.): m. opposition , hostility , quarrel , strife between; (logical) contradiction , contrariety , antithesis , inconsistency , incompatibility
hi: for
tayoH (gen. dual): of them, of those two
nityam: ind. always , constantly

prakaasha: m. clearness , brightness , splendour , lustre , light
tamasoH = gen. dual tamas: dark
iva: like