Sahih al-Bukhari Book 68, Hadith 11
A man divorced his wife thrice (by expressing his decision to divorce her thrice), then she married
another man who also divorced her. The Prophet (ﷺ) was asked if she could legally marry the first
husband (or not). The Prophet (ﷺ) replied, "No, she cannot marry the first husband unless the second
husband consummates his marriage with her, just as the first husband had done."
The wife of Rifa`a Al-Qurazi came to Allah's Messenger (ﷺ) and said, "O Allah's Messenger (ﷺ)! Rifa`a divorced me irrevocably. After him I married `Abdur-Rahman bin Az-Zubair Al-Qurazi who proved to be impotent." Allah's Messenger (ﷺ) said to her, "Perhaps you want to return to Rifa`a? Nay (you cannot return to Rifa`a) until you and `Abdur-Rahman consummate your marriage."
Allah's Messenger (ﷺ) gave us the option (to remain with him or to be divorced) and we selected Allah and His Apostle . So, giving us that option was not regarded as divorce.