Yusuf said, “By this inquiry I meant to let him (Al-Aziz) know that I did not betray him in his absence, and that Allah does not bless with His guidance the artful schemes of those who betray their trust.
Meaning:-
Betray: disloyalty, to be unfaithful in guarding, your actions hurt and disappoint them.
Artful: slyly crafty or cunning; deceitful; tricky: artful schemes. skillful or clever in adapting means to ends; ingenious: an artful choice of metaphors and similes.
Schemes: an underhand plot, a plan. (underhand meaning: done in secret)