A plain sentence could say, “The evidence made the matter clear.” It conveys the fact but does not create the picture of speech. “Naṭaqat al-ḥāl” personifies circumstances as a witness speaking aloud.
The expression intensifies the certainty and clarity of what the situation discloses: the circumstances seem to testify for themselves.
This also illustrates the literal–figurative distinction. Actual speaking belongs to a speaker; the “speech” of circumstances is transferred. Reducing “spoke” to a flat synonym of “showed” loses the rhetoric.