Maybe he means "my" as in we're all "his" children. It flows forth naturally for megalomaniacs and self-appointed demi-gods to call people sons and daughters as metaphoric class indicators. Priests, dictators, or emperors seeking to passive-aggressively indicate affinity with commoners use the term "my child" when speaking to someone of lesser station.
It doesn't even occur to him that such an utterance seems out of place and bizarre to most people because he doesn't have sons. In his mind, he's relating to our impulse to be taken care of like his children.