3 The outward sparks of her in burning fire;

in > inwardly

4 Which spent in vain, at last she told her brief, 5 That but if she did lend her short relief,

but if > unless short > immediate

6 And do her comfort, she might algates die.

do > afford (with implication of sexual service: cf. 101.51:6) algates > altogether, at any rate; hence: surely

7 But the chaste damsel, that had never proof

proof > experience

8 Of such malengin and fine forgery,

malengin > ill intent; deceit, guile fine > consummate, skilful; sheer, unadulterated forgery > fiction, mendacity