Sourcing rhymes with:
outsourcing, coursing, divorcing, endorsing, enforcing, forcing, horsing, outsourcing, reinforcing, coursing, divorcing, endorsing, enforcing, forcing, horsing, outsourcing, parsing, piercing, reinforcing
Sourcing sounds like:
saracens, scorching, scourging, screeching, scroggins, searching, seriousness, sharking, shearson's, shirking, shrieking, shrugging, surgeon's, surgeons, surgeons', surging