Dear Denise,
This is Psalm 118/119, the longest Psalm, and can be found at pomog.org online.
As you know, it is read daily by the Byzantine tradition - weekdays at the Midnight Hour, Saturday morning at Matins and most Sunday mornings at Matins following Kathismata 2 and 3.
It is also read at wakes and funerals, it being a hymn in honour of the Law of God and Christ being the only One Who perfectly kept it.
The Byzantine Church divides it into three Sections, as you will see on the above site.
The Celtic Church made prostrations after every two verses of this Psalm.
The Coptic Church prays "Glory to Thee, Lover of Mankind" ("Zoksasi Philanethrope" or something like that
) after each of the 22 sections of the Psalm that represent the 22 letters of the Hebrew alphabet.
It is recited daily for forty days after the death of someone by members of the family and always at the funeral brunches following internment.
Alex
denise