To vouchsafe is to condescend to grant something.
These writers the word in its traditional sense:
At last I am at liberty to vouchsafe to you the dozen rules in reading a political column. [NY Times]
We note that the true Prince of Darkness, Dick Cheney, has been dutifully silent, and conspicuously absent, during the recent national security festivities, to vouchsafe the limelight to Junior. [Register]
The condescension is key. Vouchsafe is not merely a synonym of grant. For example, this writer would do well to use grant instead of vouchsafe:
Yet, Western Civilization vouchsafes right of dissent, by Western values if not always by action. [San Francisco Sentinel]
Nor is vouchsafe a synonym of vouch for. These writers obviously mean that instead of vouchsafe:
Agriculture ministers from both sides have agreed that Russian and Polish vets will sign a memorandum to vouchsafe the quality of the Polish meat. [euronews]
Kerry predictably has sent his Jewish political allies to vouchsafe for his pro-Israel bona fides. [Jewish Journal]