The boys’ bodies were handed over to Israel last February. Hamas said that another body returned on the same day was Shiri’s but forensic testing showed it was not her. Shir’s body was subsequently returned.

Yarden Bibas’s message, posted to his Instagram account, began: “My beloved Kfir. Just a few months after you were born, you were evacuated from home because of a round of fighting in Gaza”.

He continued: “You got to taste solid food, you started crawling, and you even got to celebrate your brother’s 4th birthday…You didn’t get to celebrate your first birthday, so how can I mark your third?

“Kfir, I’m sorry I brought you into such a cruel world. I hope you know how much I love you and how much I miss you. I’m sure Mum,  Ariel, and Tony [the family dog] are celebrating with you in heaven. I’m sure Mum is giving you the best and happiest birthday possible, just the way she knows how.

“I love you more than anything in the world, always, forever”.

He ended the emotional message with three orange heart emoji, the symbol that has become ubiquitous among tributes to Kfir and Ariel, signifying the children’s bright hair.

The boys were killed by Hamas terrorists in captivity in Gaza no later than November 2023, according to the IDF’s forensic examination. Kfir would have been ten months old and Ariel aged four at that time. Shiri Bibas was 32. Yarden Bibas was released back to Israel after 484 days, in an elaborate ceremony staged by Hamas that was widely condemned.