Tzeruf is a 5800 year plus kabbalah meditation system referred to in the bible as - calling in the name of the Lord. Seth, Abraham, & Isaac are described as doing this in the Bible.
Tzeruf is a verbal meditation that mixes the name of God (or one of it’s cognatives) with other Hebrew alphabet letters which represent the 22 spiritual aspects of creation. This mixing is accomplished by arrainged and organized tables that contain Hebrew alphabet letters and the shem hamephorash, or Gods true name.
The organizational methods vary but mainly consist of mixing God's true name with 1. a word, 2. group of words, usually a portion from the bible, 3. verses from the bible, and 4. the whole Hebrew alphabet sequence.
The length of time to complete a table segmented kabbalah meditation is anywhere from 5 minutes to an hour depending on the intensity desired.