God does give us impressions but not that we should act on them as impressions. If the impression be from God, He will Himself give sufficient evidence to establish it beyond the possibility of a doubt.
How beautifully we read, in the story of Jeremiah, of the impression that came to him respecting the purchase of the field of Anathoth, but Jeremiah did not act upon this impression until after the following day, when his uncle's son came to him and brought him external evidence by making a proposal for the purchase. Then Jeremiah said: "I knew this was the word of the Lord."
He waited until God seconded the impression by a providence, and then he acted in full view of the open facts, which could bring conviction unto others as well as himself.
God wants us to act according to His mind.
We are not to ignore the Shepherd's personal voice, but like Paul and his companions at Troas, we are to listen to all the voices that speak, and "gather" from all the circumstances, as they did, the full mind of the Lord.