“Davar” is “thing”.
When you want to say “the same thing” or “the same” you should say “oto davar” for both masculine and feminine.

(f) – Ha’mizvada sheli hi oto davar kmo shela^ (kmo shela^ = like yours).
(m) ha’sefer sheli hu oto davar kmo shela^.

For feminine I say “hi” (sounds like “hee”) – ha’mizvada sheli hi…
For masculine I say “hu” – ha’sefer sheli hu…

so for instance if you speak about the same mizvada do you say

ha’mizvada sheli he ota davar?

Or am I now thinking to male/female

bye,
Conny