Not graded
Bulugh al-Maram 1073b
وَفِي لَفْظٍ لِأَحْمَدَ : { طَلَّقَ أَبُو رُكَانَةَ اِمْرَأَتَهُ فِي مَجْلِسٍ وَاحِدٍ ثَلَاثًا , فَحَزِنَ عَلَيْهَا , فَقَالَ لَهُ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -" فَإِنَّهَا وَاحِدَةٌ } وَفِي سَنَدِهَا اِبْنُ إِسْحَاقَ , وَفِيهِ مَقَالٌ 1 .
1 - ضعيف . رواه أحمد (165) وليست علته في ابن إسحاق ، وإنما له علة أخرى.
A wording by Ahmad has:
Abu Rukana divorced his wife with three pronouncements, in one sitting. Then, he was grieved about her and Allah's Messenger (ﷺ) told him, "They (the three pronouncements) are reckoned as a single (utterance of divorce)." [The two Ahadith have Ibn Ishaq, in their chains of narrators, and his reliability has been questioned].
Cited in Bulugh al-Maram (No. 1073b).