Non enim in justificationibus nostris

Source: 
Washington, D.C., The Library of Congress - Music Division, M2.1 XI M4 [formerly M2.1 XII M1]
Folio: 
002r
Sequence: 
6
Feast: 
De Prophetis
Genre: 
V
Position: 
01
Cantus ID: 
007471a
Mode: 
?
Manuscript Reading Full Text (standardized spelling): 
Non enim in justificationibus nostris prosternimus preces ante faciem tuam sed in miserationibus tuis multis
Manuscript Reading Full Text (MS spelling): 
Non enim in iustificationib; nostris psternimus preces ante faciem tuam s; in miserationib; tuis multis. Exaudi
Indexing notes: 
"justificationibus" is spelled "iustificationib;" in the MS. Is this an abbreviation I should expand? MS Spelling: Nostris has weird symbol, I think it is a short-form so I have included proper spelling in MS Spelling