“Special mercy” as object — prefer saying grace-promises fiducially applied
“Special mercy is justifying faith’s proper object” means: unlike historical faith, it applies divine-mercy promises personally — before justification trusting sins will be remitted, after believing they have been.
The phrase is obscure and open to slander.
Le Blanc prefers (with many): principal object = grace-promises apprehended with practical fiducial assent and applied to oneself — same substance, clearer words.
Latin
XCII. Quod autem multi ex Protestantibus dicunt, misericordiam specialem esse proprium objectum fidei justificantis, per hoc non aliud significare volunt, quam proprium esse fidei justificantis, prout distinguitur a fide historica, ut promissiones divinae misericordiae sigillatim cuique credentium applicet: ea ratione ut ante justificationem peccata sibi esse remittenda confidat, & post justificationem credat sibi esse remissa. Sed quoniam hic loquendi modus obscurus est, & etiam calumniae obnoxius, mallem, quod multi faciunt, ab eo abstinere, & simpliciter dicere potissimum fidei justificantis objectum esse promissiones gratiae, prout sunt assensu practico & fiduciali a credente apprehendendae, & ipsi applicandae, quod eodem recidit.