Nafi' narrates from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that he divorced his wife while she was in the house of Sayyidah Hafsah (may Allah be pleased with her). That was his route to the mosque, so he used to take the other route, behind the houses, disliking to seek permission from her, until he took her back.
(b) Ata bin Abi Rabah and Amr bin Dinar (may Allah have mercy on them both) say: Nothing of her is lawful for the man as long as he has not taken her back.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرجعة / 15186