I am a Landlord in Harford County, Maryland and I am about to evict a tenant. The tenant is telling us if he files for Bankruptcy that we can not evict him on Monday. What is the law concerning evictions and bankruptcy in Maryland?

You will still have to go to housing court to get a court eviction, when he files you will not be able to collect past money he owes you, but from the day he files, any future bills are not protected, merely the bills prior to filing,
The day he files, he owes for that time in rental, not protected.
Idea how to fight his idea that you are evicting for past due, you are evicting for current unpaid rent, rent is always paid in advance

I would move ahead,