Bruce Jenner is giving his daughters Kendall and Kylie an unorthodox Father’s Day gift.

The Keeping Up With the Kardashians father, along with other celebrity fathers like Ethan Hawke, Mario Lopez, Richie Sambora, and Aaron Sorkin, has penned a letter to his girls for

In his letter, the former Olympic star writes about having 10 children and raising them over the course of 34 years. What a legacy! "Every girl has been totally different, both in personality and lifestyle. And that’s the thing I’ve learned to value most: be true to yourself, be your own person — and be caring to others, as well," Bruce writes.

Credit: Frazer Harrison/Getty Images Photo: Kendall and Kylie Jenner Walk the Runway in the 2013 Heart Truth Fashion Show

He advises Kendall and Kylie to "develop a passion," and also stresses the importance of "picking the right partner to share" their lives with.

"Your mom [Kris Jenner] and I have been together for 23 years, and our relationship has constantly changed and evolved. But we have been able to make it through those adjustments because of a deep love and caring for each other. We are still as committed as ever."

Bruce says that while he’s "so proud" of his daughters, they "will face obstacles." He says, "Trying things outside of your comfort zone is essential, because your ability to grow as a person is directly related to the amount of insecurity you can handle."

Bruce concludes his letter by saying, "So be strong and fearless on this journey we call life."You can read Jenner’s full letter — and the notes from the other celeb dads — here.What do you think of Jenner’s advice to Kendall and Kylie?

Source: Gossip Cop

Credit: Photo: Kris and Bruce Jenner Dish on Kardashian Shows