(2)All bills and charges of attorneys-at-law, managers, accountants, auctioneers, brokers, and other persons, not being trustees, shall be taxed by the prescribed officer, and no payments in respect thereof shall be allowed in the trustee's accounts without proof of such taxation having been made. The taxing officer shall satisfy himself before passing such bills and charges that the employment of such attorney-at-law and other persons, in respect of the particular matters out of which such charges arise, has been duly sanctioned. The sanction must be obtained before the employment, except in case of urgency, and in such cases it must be shown that no undue delay took place in obtaining the sanction.