The Messenger of Allah ﷺ restored his daughter Zaynab to Abul'As on the basis of the previous marriage, and he did not do anything afresh. Muhammad b. 'Amr said in his version: After six years. Al-Hasan b. 'Ali said: After two years.  

رَدَّ رَسُولُ اللَّهِ ﷺ ابْنَتَهُ زَيْنَبَ عَلَى أَبِي الْعَاصِي بِالنِّكَاحِ الأَوَّلِ لَمْ يُحْدِثْ شَيْئًا قَالَ مُحَمَّدُ بْنُ عَمْرٍو فِي حَدِيثِهِ بَعْدَ سِتِّ سِنِينَ وَقَالَ الْحَسَنُ بْنُ عَلِيٍّ بَعْدَ سَنَتَيْنِ