Be ye mindful. This was specially for this occasion. In Psalms 105:8, where it is for more general use, David (in editing) changed it to "He hath remembered". See note on 1 Chronicles 16:7.
Related Commentaries of 1 Chronicles 16:15
1 Chronicles 16:15
15 Be ye mindful always of his covenant; the word which he commanded to a thousand generations;