Recommendation: not recommended, buy Yacov's 3rd book which is much better (Genesis Factor).
Yacov Rambsel is a Jewish Messianic rabbi/pastor from Texas, who has been involved in the Bible code for over 20 years. He does all his searches by hand, which greatly limits the quality and quantity of findings. With a computer, one can do more in a day, than a person can do by hand in a year.
I admire Yacov Rambsel for his dogged determination and sincere beliefs in the Bible. In both books he's written, Yeshua: The Name of Jesus Revealed in the Old Testament, and His Name is Jesus, he intertwines many insights from his years of Bible studies. Yeshua is Yacov's first book on the Bible code, published in 1996. It's available at Amazon.com and Barnes&Noble.com.
Yacov Rambsel and Grant Jeffrey have been the targets of many attacks over their simplistic Bible codes, and for claiming far more than is prudent from their findings. I do not wish to join the attacks on Yacov Rambsel or Grant Jeffrey. They both realize now that they vastly overstated their findings. In Yacov's case, he is an early pioneer in the field of the Bible code. When standing on the shoulders of others who were earlier researchers, one does not kick them in the head. Later research will always be far better and more sophisticated than the early research by people like Yacov Rambsel.
I cannot recommend his book Yeshua: The Name of Jesus in the Old Testament, for purchase, since it has been far surpassed by current Bible code research and even later books on the Bible code. If one were to purchase a book by Yacov Rambsel, then I recommend his second book, His Name is Jesus, over the first one. In it, he does have at least one interesting matrix on Yeshua and all the people involved in His ministry, in Isaiah 53.
Grant Jeffrey has changed his tune with regards to tying in a few words at ELS with the surface text, and then calling it a valid Bible code. He no longer teaches that concept nor believes it to be true. What we found in later codes research is that sometimes you can make a correlation between codes and the surface text, but many who did it had to stretch to make that happen. In other cases, there was simply no correlation between the Bible code matrix and the surface text. If it is not true all the time, then it is not true. We do not believe that the Bible code and surface scriptures are tied together in a meaningful way. I and others even try to avoid using any terms at an ELS of +1 in Bible code matrixes, which is the surface text.
Also, having just a few terms in a matrix and calling it a valid Bible code is not justified. One can find a few random words grouped together using any text in any language. Valid Bible code matrixes involve finding large scale clusters of associated terms in close proximity. Personally, I will not even consider looking at a Bible code matrix for validity, unless it has at least 10-15 terms minimum (and not all small 3-4 letter words easily found anywhere).
Casual readers about the Bible code may have an idea that the Bible code consists of simplistic matrixes of 4-8 terms, as shown in books like The Bible Code by Michael Drosnin. However, current Bible code researchers require much tougher standards than that.
I admire Yacov Rambsel's faith, his love of God, and his pioneering spirit. However, most of the concepts he identified in the Bible code are likely not true. His books may be good as resource material showing early work in the Bible code.