AceShowbiz - Despite their tumultuous marriage, Khloe Kardashian is among the people who are happy to learn of the success of Lamar Odom's newly-released memoir "Darkness to Light". The mother of one even sent him congratulatory messages on Instagram when the book made it onto the New York Times Best Sellers book list, much to everyone's surprise. And apparently, the NBA star was also surprised by the move.

At the same time, according to HollywoodLife.com, Lamar was "so happy and excited to see that Khloe congratulated him on his book so publicly." A source told the gossip site that the now-sober star was "really, really nervous to see how the Kardashians would respond to his book coming out," given that he talked about the famous family in the book. "It made him feel so good for Khloe to put that out there," the source shared.

"He never wanted them to feel disrespect and he was hoping his book release would make them reach out, and he's so happy to see how well it has been received by Khloe," the informant continued. "It honestly surprised him that she did that, but he's so happy to be back in her good graces. It made his day to see that and gives him hope that maybe they can see each other in person soon. He's in a really great place, so that would be the icing on the cake for him."

Detailing his struggles with fame, sex, pain and drugs among others, "Darkness to Light" hit the shelves on May 28. Lamar gave Khloe a shout-out when he announced that his book had become the New York Times' No. 6 best-seller, writing, "Your continued support and love is appreciated! It took a lot of courage for me to get so raw and candid with you all but I wanted you guys to get MY true story!"

The "Keeping Up with the Kardashians" star responded with a hearty "Congratulations Lammy!" before adding, "Keep shining."