What is the legal effect if a husband says, 'You have divorce of the Sunnah' (Anti taliqun talaqa s-sunnah)?

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If the husband states, 'You have divorce of the Sunnah' (Anti taliqun talaqa s-sunnah), one divorce occurs during a period of purity in which no intercourse has occurred. However, if the husband intends the triple divorce (Thalath), then three divorces occur. This is because the mention of the verbal noun (masdar) encompasses both the singular and the plural, unlike the previous phrasing.