To Monk Gao Xian
One can stay focused and remain unruffled by the distractions of outside world with aim and the will. Whose who amounted to success are those who had sticked to their goals, while those who changed their mind the moment saw something new are either ineffectual or ignorant.
Zhang Xu specialized in nothing but cursive script, in which he gave vent to his joy, anger, embarrassment, sorrow, resentment, longing, tipsiness, boredom, indignation, or whatever welled up in his heart. From his observation, he implied in his handwriting the forms of mountains, rivers, precipices, valleys, birds, beasts, insects, fishes, blossoms, fruits, the sun, the moon, chain of stars, wind, rain, water, fire, thunderbolt, sword dance, or anything that is changeable, admirable and wondrous. This is why his calligraphy is divinely changeful and inconceivable. He adhered to his practice throughout his life, which repaid him the everlasting fame.
I am quite doubtful about your calligraphic practice. Imitating his handwriting without reliving his spirits may not necessarily get his essentials. Zhang's calligraphy grew out of his take on things - knowing where his interests was he strove for it; with emotion surging in his heart he was ready to defend it; and in spite of his losses he stayed indomitable.
As a Buddhist monk you may have seen through the vanity of the world; therefore you must probably be indifferent toward fame and wealth, and find nothing worthy of devotion in this mortal life. These indifference and nothingness should give you an irremediable dispiritedness and take imagery away from your practice. I heard that Buddhists are capable of magic in many ways. If you are capable of it too, the matter will be beyond my knowledge.
Zhang Xu ( - )