Staročeský traktátek o křivé přísaze

This article deals with a short Old Czech treatise on perjury which is written in a manuscript dating from the first half of the 15th century (Prague Castle Archive, Metropolitan Chapter Library by St. Vitus, Number H 10, fol. 270v). It is the unique coherent Czech text contained in this codex which according to its writing originated between the years 1416-1450. The analysis shows that it is a translation of a chapter of the second part of the Decretum Gratiani (causa XXII, questio V, capitulum V) not found elsewhere. The Old Czech text is compared with the Latin wording and with a passage of identic contents in the Czech work by M. Jan Hus called Výklad delší na desatero přikázanie. The executed analysis shows that some details in the Staročeský slovník and in the critical edition of the work by Hus need to be revised.