The blessings promised are not only for this life, but will transcend this life. In verse 23 Yahweh notes that some blessings will be granted “in the end”—meaning the time when the earth’s purposes are fulfilled. It will be the time of the Triumphal Messiah. (See commentary accompanying 3 Nephi 12:48.)
Translation: The imagery of the right hand comes from the ancient conceptions of the right hand as good and the left hand as evil. The Latin word for “left” is sinistra, which was adopted into English with an obviously pejorative character. Thus, it is a blessing to be on Yahweh’s right hand. This conceptual division between the left and the right is well known from the Old World, but less so from the New World.
There is little literature on the meaning of the left hand in Mesoamerica, but there are hints that it was not considered evil, but that it may have been a sign of a connection to the powers of the other world. For example, the left-handed warriors of the Mexica were considered the most fearful, most likely because their left-handedness gave them a military advantage. The name of the Mexica tribal deity was Huitzilopochtli, meaning “hummingbird on/of the left.” This context is positive for the Mexica. A fascinating possibility comes from an analysis of the various stelae at the site of Izapa, a much later description of the underworld from the Codices Matritenses, and the Mesoamerican fascination with mirrors.
In Izapa, a preponderance of actions are performed with the left hand. Either the Izapans were statistically left-handed more than any other known population, or the depiction of actions by the left hand had a distinctive significance. The Codices Matritenses describe the underworld as a place of reversals from the real world. And finally, the Mesoamerican mirror of polished obsidian or hematite has symbolic connections to the primordial waters and the underworld. The mirror effect is so well known that we understand a “mirror image” to transform right to left and left to right. In this context, the left hand may be a representation of a connection to the otherworld.
What would these possibilities mean for this passage? I hypothesize that Joseph translated the concept, using an image that was familiar to him, though not necessarily the wording on the plates. Of course, we do not know that wording; but in the social context of Mesoamerica, it seems unlikely that the Old World imagery of “right is good/left is bad” would have survived long enough to be recorded in this time period.