I belive you're looking for Hyperion by <PERSON>.
https://www.goodreads.com/book/show/77566.Hyperion
On the world called Hyperion, beyond the law of the Hegemony of Man, there waits the creature called the Shrike. There are those who worship it. There are those who fear it. And there are those who have vowed to destroy it. In the Valley of the Time Tombs, where huge, brooding structures move backward through time, the Shrike waits for them all. On the eve of Armageddon, with the entire galaxy at war, seven pilgrims set forth on a final voyage to Hyperion seeking the answers to the unsolved riddles of their lives. Each carries a desperate hope—and a terrible secret. And one may hold the fate of humanity in his hands.
Here's a link to the character page on TV Tropes. 322
http://tvtropes.org/pmwiki/pmwiki.php/Characters/Hyperion
The character you've remembered is <PERSON>.
A Jewish scholar. His daughter, <PERSON>, was afflicted with an illness dubbed the Merlin Sickness that caused her to age backwards, which he desperately hopes to cure. After having a dream about sacrificing his daughter to the <PERSON> similarly to the Biblical sacrifice of <PERSON>, he decides to do so in hopes it will cure her somehow.
<PERSON> was a scientist studying the ruins. After an accident she begins aging backwards and forgetting everything that has happened to her, she would essentially wake up each new day believing it was yesterday. The phrase you remember was mentioned in a poignant passage where she forgets this call and response, because from her point of view she's never heard it before.
The seven pilgrims arrive some distance from the Time Tombs, because they're attacked on route and have to abandon ship. They travel across the surface by numerous transport methods including by boat.
The Time Tombs themselves were, since <PERSON>'s accident, inaccessible. The phrase time locked may have been used. The travelers believe that they as a group will be able to enter because of their varied and unique connections with the Tombs.
The Shrike is the protector of the tombs and is a lethal assassin, not bound to human rules about time and kills with blades described as razors many times throughout the book. 45