St. George Temple president David H. Cannon recounts how Apostle George F. Richards had "criticized [him] very severely for not adhering to the unwritten part of the ceremonies as he had been instructed to do." He tells the assembly of local Church leaders that Richards had instructed him to either burn the old rulings and instructions or send them to Salt Lake-"If we want any information, not contained in the 'President's Book' we will refer to the authorities of the Church for that information, but not refer to any of the old rulings."
St. George Stake president Edward H. Snow (who became the temple president in 1926) then mentions one of the recent changes, "in no longer praying that the blood of the prophets and righteous men, might be atoned for, because this prayer has been answered and [is] no longer necessary." As if to pass approval on this change, Cannon recalled comments by Anthony W. Ivins (second counselor in First Presidency) given at a conference in Enterprise, stating that Ivins "took exception to the way the Law of Retribution was worded, and said he [Ivins] thought the language was harsh and that the authorities [had] thought of changing that" Three years later a letter from Apostle Richards to all temple presidents directed that they "omit from the prayer circles all reference to avenging the blood of the Prophets. Omit from the ordinance and lecture all reference to retribution"
[On This Day in Mormon History, http://onthisdayinmormonhistory.blogspot.com, based on Michael Quinn's Mormon Hierarchy vols 1 & 2]