Would you allow a check to resist?

A third party (spirit being) thats ambiguous in its relationship to my player party seeks to let them receive information this is beneficial to their goals and cause via a form of mental influence.

The party is currently in a tavern which is in a very dangerous region but under the protection of a sapient spirit tree, the spiritual presence of which wards off any outside influence.
This spirit tree wishes to impart knowledge to the player party which would benefit them but the only way it can do this is by intruding on their minds.
Would you, as the GM, allow your player characters to make a save to resist this mental influence considering that its beneficial and harmless but they would most likely be uncomfortable allowing it?