What role does «غَيْرَ مُفْسِدِهَا» play in the rain-prayer example?

Supplementary Practice 1: Applied Analysis of Faṣl, Waṣl, Ījāz and Iṭnāb

• Iḥtirās: it excludes the possibility of destructive rain
• Repetition of the original wording
• An omitted conditional answer
• Coordination of two declarative clauses