《资治通鉴·后晋纪·后晋纪二》
张谊上书说： 北狄契丹有援助立朝的功劳，应该表面上与他敦信修好，内部要认真加强边境上的戒备，不能自己放松警惕，因而开启他的兴兵侵犯之心。 
谊上言： 北狄有援立之功，宜外敦信好，内谨边备，不可自逸，以启戎心。 
Zhang Yi mentioned in his letter: Beidi Qidan has the merit of supporting the foundation of the dynasty. He should show his trust and make peace with him on the surface. However, he should strengthen the guarding on the border and never relax his vigilance so that he can start a war to invade.