Note to stanza
: As suggested by Sperber and Finnur Jónsson (Skj B), í læstu briefi presumably refers to the obscure meaning of the first half-st. The phrase must be an Icel. calque on Lat. litterae clausae, letters close, that is, private letters, addressed to one or two individuals only and closed or folded and sealed, by contrast with letters patent, open letters or documents affixed with a royal or other seal, issued by a monarch or government.