It’s just another way for the orange criminal to obstruct justice. Make it clear to all the possible co conspirators that could be compelled to testify against him that he fully intends to pardon them if they take the fall.
This is not a new tactic for this criminal. He had no problem telling his followers during the campaign that he would cover their legal fees for attacking opponents.
The firing of Comey, the thinly veiled threats against Mueller, the hiring of attorneys to did up dirt against government attorneys, the setting up reasons to fire Sessions so he can appoint a loyal replacement and now making it clear to possible witnesses that he will pardon them if they cover his ass. There is nothing this russian mob Don won’t do to obstruct justice.