The first dative "mir" ("to me ") expresses the speaker's deep commiseration, the second dative"meinem Sohn " ("to my son") names the actual object of the plea.
The first dative "mir" ("to me ") expresses the speaker's commiseration (much like the"dativus ethicus " in Latin, see below). The second dative"meinem Sohn " ("to my son") names the actual object of the plea.