Was Thomas Jefferson able to free his slaves?

In an interview with Dave Reuben, the much maligned Glenn Beck made the claim that Thomas Jefferson could not release his slaves because it was illegal for one to do so while in debt.

Is it true?

This source quotes the law itself

This law allowed slave owners when they were alive to free their slaves, provided slaves were of sound body and older than 18 if a female and older than 21 if a male, but not above the age of 45. Thus, Jefferson could have freed many of his slaves within the law while he was alive.

 It also points out that Jefferson, in fact, freed two slaves. It's kind of hard to argue that Jefferson was unable to free his slaves when he actually freed 2.

This three-part, citation heavy series is also very good.