"I'm sorry for bringing you into such a cruel world," ex-hostage Yarden Bibas lamented in a post on Instagram for his slain son Kfir's third birthday on Sunday.

Kfir, his older brother, Ariel, and his mother, Shiri, were all murdered by Hamas terrorists after being taken hostage on October 7. Yarden Bibas was the only survivor of the family.

"You were forced to evacuate your home because of a round of fighting in Gaza just a few months after you were born," Bibas mourned. "You managed to taste solid food, you started to crawl, you reached your brother's fourth birthday. You didn't reach your first birthday, so how can I acknowledge your third?"

Kfir and Ariel Bibas murdered by Hamas after just a month

Kfir was kidnapped and taken hostage when he was nine months old. The IDF confirmed that he and his brother were murdered in captivity by Hamas only a month after their abduction.

"I'm sure that Mom, Ariel, and Tony are celebrating for you in the Garden of Eden," Bibas said. "I'm sure that Mom is giving you the best and happiest birthday possible, just like she knows how to do."

"I love you the most in the world, always," he concluded.