What is the Quranic miracle in the use of conditional tools in verse 131 of Surat Al-A'raf?

The Qur'an is miraculous in its words, structure, and meanings, and humans may grasp some aspects of its miraculousness. Regarding the verse: "And when good came to them, they said, 'This is ours.' But if evil afflicted them, they augured ill of Moses and those with him. Unquestionably, their evil omen is only with Allah, but most of them do not know," the word "إذا" (if/when) was used with "good" (الحسنة) to indicate certainty of its occurrence, while "إن" (if) was used with "evil" (السيئة) to indicate hesitation or doubt about its occurrence, because the occurrence of evils (dislikes) is rare compared to good things (blessings).