Thanks for all the responses regarding healthy meals for my dad. How do I find someone to go in and prepare meals 3 days a week?

How far away do you live from dad?
Is he able to heat up his own meals?
You do not indicate any medical problems he has other than he is being released from rehab. A little more info on that would help greatly.
Can you fix meals and freeze them in easy to heat containers or in Zipper top bags so he can put them in a pan or bowl and heat them up?
If he needs other help hiring a caregiver to go in a few times a week to make a few meals, clean up and maybe do laundry and in general check in on him.
There are plenty of meal delivery services if he can fix his own meals.

I live in SWJersey. I think this is the company delivering a meal at my daughter's apartment complex.

https://www.momsmeals.com/our-programs/

Call ur County Office of Aging and see if they know of any programs other than meals on wheels.

Maybe go onto Nextdoor.com and ask for recommendations.