A VERY FINE IMPERIAL WHITE JADE 'ZI QIANG BU XI' SEAL QING DYNASTY, QIANLONG PERIOD

of square form, surmounted by a superbly carved pair of addorsed dragons, each exceptionally well carved with bulging eyes and flaring nostrils above curling whiskers and a partially open mouth revealing sharp fangs and even rows of teeth, the scales and flowing mane defined by fine incisions, the two scaly bodies intertwined and crouching low on the haunches, pierced through the centre with an aperture, the square seal deeply and crisply carved with the characters Zi qiang bu xi ('Self-strengthening Never Ceases'), the stone of an icy, pale celadon tone with small white inclusions and natural veining

Removed from the Shouhuangdian (Hall of Imperial Longevity), Beijing, 1900.

There are just a few minute nicks to the corners of the seal face with a 1mm nick to one of the corners that has been slightly polished down. The actual colour of the stone is a tinge greener and warmer in tone than in the catalogue illustration.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

This seal belongs to a set of three seals and is paired with Bazheng maonian zhi bao (Treasure of the Eighty-year old who concerns himself with the Eight Signs).  It is carved with the characters Ziqiang buxi (Self-strengthening Never Ceases), and is a Yajiao zhang; it is used to make impressions at the right or left corner of a painting or piece of calligraphy.   

Ziqiang buxi (Self-strengthening Never Ceases) was derived from the Yijing (Classic of Changes), Hexagram 1 Qian (Pure Yang), Xiangzhuan (Commentary on the Images): "The action of Heaven is strong and dynamic.  In the same manner, the noble man never ceases to strengthen himself."  Emperor Qianlong ordered the seal of Bazheng maonian zhi bao (Mindful of the Signs of the Eighth at Eighty Seal) to be made during his eightieth birthday in the fifty-fifth year of his reign [1790].  In accordance with the precedence of making Youri zizi (Still busy and hardworking every day) the secondary seal of Guxi tianzhi zhi bao (Seal of the Son of Heaven at Seventy) when he was seventy years old, Ziqiang buxi was similarly made the secondary seal of Bazheng maonian zhi bao.  Emperor Qianlong explained, "Although there had been "Self-strengthening Never Ceases" seals already for some time in palaces for use on pieces of calligraphy by the emperor, in the year gengzi [1780], I had Guxi tianzi zhi bao carved and paired with a secondary Youri zizi seal, so when I approached eighty and had Bazheng maonian zhi bao seal carved I likewise had it paired with a secondary Ziqiang buxi seal.  Although self-admonitory expressions are often found in the Classics, the very first image that occurs in the Classic of Changes is the one for Qian (Pure Yang, Heaven), and nothing surpasses it for expressing the fact that it is of the most vital importance to emulate the strength and dynamism of heaven."  "Once I had the Bazheng maonian zhi bao seal carved, I had it paired with the secondary Ziqiang buxi seal, just as when I reached seventy I had the Guxi tianzhi zhi bao carved and paired with the secondary Youri zizi seal, for both secondary seal engravings state the determination to be ever mindful of the fear of Qian (Heaven)."  The Emperor's choice of Ziqiang buxi as a secondary seal was done to express his determination that before relinquishing power, he would not become indolent, but would always be mindful of his people and diligently do his best to govern.