策驽砺钝

Explanation: Driven horse, sharpen blunt instrument. Refers to the reluctance, to engage. Dull, low energy of the horse; blunt, not sharp knife. 　　Source: Song Yuefei "Yushu Mita Postscript three things": "His Majesty the pro-spending Chen Fu Meng Han, laying the above three sub-Mita matter of sufficient food, overlooking to give Chen, Chen'm not making dull dull grind, Yang Vice holy event."