Al-Sha'bi narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) concerning a man who gave his wife three divorces before consummating the marriage. He said: "It was a right in his hand which he has used; and when he divorces after that, it is nothing."
Sufyan said: "Tatra" (in succession) means: "You are divorced, you are divorced, you are divorced"; the first divorce separates her, and the other two have no standing. Imam al-Shafi'i (may Allah have mercy on him) reports from Abu Yusuf (may Allah have mercy on him) concerning a man who says to his wife before consummating the marriage: "You are divorced, you are divorced, you are divorced," that the first divorce takes effect and the remaining two do not. This is also the view of Imam Abu Hanifah (may Allah have mercy on him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الخلع والطلاق / 15087