John Trapp on Isaiah 48:10

Ver. 10. Behold I have refined thee, but not with ſilver] Much leſſe as gold, which is wont to be fined moſt exactly,Non agam ſummo jure tecum. Jun. and to the uttermoſt; becauſe theſe precious mettles will not periſh by fire. But thou haſt more droſſe in thee than good oare: therefore I have refined thee with favour, Pſal. 118.18. Ne totus disperires, leſt I ſhould undoe thee: for if thy puniſhment ſhould be commenſurate to thine offence, thou muſt needſly periſh.

I have choſen thee in the furnace of affliction] i. e. In affliction, which is as a furnace or crucible. See Ezek. 20.37.