This is one of my all-time favourite quotes. We sometimes can get into a debate about the “spirit” of the law and the “letter” of the law. Which is better? Which is right? Which do we follow?
Apparently this was written to one of Joseph F Smith’s sons who was on a mission. He had asked his dad about whether to anoint with oil with the right hand.
The question you ask about anointing seems very simple to me. I think it is the general practice to pour the oil with the right hand. I suppose because most people are right-handed. But there is no law or rule against anointing . . . with the left. We shake with the right hand. In the endowments the signs and tokens are made and given with the right hand. When we lay but one hand on the sick it should be the right. We take the Sacrament with the right hand. The practice makes the rule. But always remember that it is not the rule, or practice, which gives life or force, but the true spirit. There is no good in splitting hairs nor in tickey-technical rules. “The letter killeth, but the Spirit giveth life.”
Scott Kenney, ed., From Prophet to Son: Advice of Joseph F. Smith to His Missionary Sons, p. 93.
Church History and Modern Revelation, 1:103.
The practice makes the rule, but the rule doesn’t give force. Only truth or the Spirit gives force. I guess according to President Smith, the debate is over… the Spirit wins!