Elaborate Verses used with the Offertory

Hello all,

I have recently been finding a number of offertory chants sung with elaborate psalm verses (see linked example below). Since modern graduals do not include any verses to go along with the offertory antiphons, I have been wondering where these could be found, and why they have not been included in the modern presentations of the Gregorian repertoire.

https://www.youtube.com/watch?v=812YstXutCI

Thank you,
CantorCole