Islamically, does a three year old get rewarded by Allah swt for use of islamic phrases?

Salaams. I'm been teaching my son to say "mashAllah" "Alhamduillah" "inshAllah" etc since he was tiny and now he uses these phrases appropriately and meaningfully etc. He also says a special prayer before sleeping thanking Allah swt for all the nice things that he has and offering blessings to the Prophet Mohammed pbuh. I'm sure most Muslim's do this - I'm a revert btw. Just out of interest, will he and/or I receive any reward for this or is he perhaps seen as a little too young to understand and be responsible for his actions? (Allah swt knows best)