My paper is devoted to the issue of susbstantial words. This concept appeared in one of the texts of St. John of the Cross. Fr. Józef Tischner, who not only commented on the texts of the great mystic about “substantial words”, but also taught where to look for such words. Tischner’s thought belongs to the tradition of the “philosophy of dialogue” initiated by Ferdinand Ebner. It is worth looking for traces of thinking in the category of “substantial words” in Ebner’s texts. Although he does not use this phrase, he writes about words in such a way that it is clear that he attributes “substantial” power to them. The order of considerations will be as follows: first, I will discuss John’s understanding of “substantial words”, showing the context in which he addressed this issue, then I will recall and comment on Tischner’s texts in which he writes about “substantial words”, and finally I will discuss these fragments of Ebner’s works in which one can find intuitions similar to those emerging from the texts of St. John of the Cross and Józef Tischner. Discussing the views of these three thinkers, I will try to show what is the specificity of “substantial words” whose utterance is attributed to God. I will also try to answer two questions. The first concerns how one should accept the “substantial words” spoken by God. The second is the question of what must happen for our human words to participate, at least to some extent, in the substantial power of God’s words.