Noa Argamani, who was held in captivity for part of the time with Itay Svirsky, whose body was returned to Israel on Wednesday, parted from him in a post on Instagram.
"Dear Itay, during our shared stay in captivity, we imagined together thousands of situations, how we would return together to Israel, how we would meet for coffee once it's all over, and how we would laugh about it all. We didn't think for a moment that this is how you would return to Israel - as a body.
"Thank you for every shared moment together, you were a friend to me, you were a big brother to me in that dark place. You taught me so many things that I will take with me, no matter where I go. Now you will get a proper burial in Israel," Argamani wrote.
Earlier in the day, the IDF cleared for publication that Svirsky's body was recovered in a military operation from Gaza.
The ISA and IDF stated: "During an ISA operation supported by the IDF, the body of Israeli hostage Itai Svirski was recovered from the Gaza Strip and returned to Israel for burial. Alongside the operational efforts, the Hostages and Missing Persons Unit within the IDF's Manpower Directorate, responsible for supporting the families of hostages, operated alongside the Institute of Forensic Medicine and the Israel Police throughout the identification process. ISA and IDF representatives delivered the news to the family earlier today."