The author examines some peculiarities of the liturgical dialogues before anaphora and Communion in the ‘Testament of our Lord’. The main peculiarity of the former is the exclamation ‘Sanctifications in the holies’ ( ) which may correspond to cγιασμοL tν τοTς cγίοις of the original Greek text. It is shown that this exclamation, reminding the exclamation ‘Holy things for the holy’ which is an essential element of the Eastern eucharistic liturgies beginning from the 4th century, is an allusion to the trisagion of Isaiah 6:3 (Sanctus). The conjecture is put forward that it was transferred from the dialogue before Communion where the words ‘Holy things for the holy’ are absent. Such a transfer could be possible if the compiler was familiar with the introductory dialogues containing warnings against unworthy participation in the Eucharist, i.e. carr ying the same meaning as the exclamation ‘Holy things for the holy’. It is shown that such warnings could appear in introductory dialogues in the process of anaphoral development in the first three centuries. The compiler of the ‘Testament of our Lord’ added such a warning and reformulated it so that it became an allusion to the Sanctus. The reasons which could induce the compiler to do so are discussed. Possible explanations of why the Sanctus is absent in the anaphora itself are also given. The dialogue before Communi on, except that it does not contain the words ‘Holy things for the holy’ , is remarkable in that it may go back to Didache 10.6 or some other ancient liturgical dialogue resembling that in the Didache 10.6.