Shalom to all, I am wondering if anyone can shed some light on the following issue: In Keses Ha'sofer 8,5 a scenario is discussed in which one wrote a rei"sh and subsequently changed it into a dale"d by adding an akev on the back etc. He concludes, that although one is not required to erase the whole thing, rather one can erase the akev together with one of the two limbs of the rei"sh, nonetheless " hamachmir... tavo alav beracha ". My understanding of this is: that since there are opinions (i.e. Rada"ch) who would deem it " miktzas ha'os be'chak tochos " to erase only some and leave some to be included in the final letter, therefore, there is virtue, albeit not required, to erase the entire letter before rewriting it. Now, just 3seif'im later, regarding " me"m pesucha shenistema " Keses rules, that although the me"m is written in two distinct parts (and therefore, only the latter part of the me"m...