This is how a modern Hebrew speaker would understand the verse.
It is curious that the Trinity is one of the main concepts in many branches of Christianity, and though there are possible hints and allusions to this in the Christian Bible, there is nothing really clear cut. By "clear cut" I mean something along the lines of the opening statement of the ten commandments:
I am the Lord thy God, which have brought thee out of the land of Egypt, out of the house of bondage.
On the other hand, traditions outside the written holy books do have a lot of weight in many religions, including Judaism, Islam, and Christianity.
That's true. And it's helpful imo to at least understand the authorized story of how teachings such as the Trinity, that are not at all clearly set out within Christian Scripture, nonetheless wound up being authoritative for the Christian Church.
Christ Jesus gave His own teaching authority (which is God's teaching authority) to His Apostles, and while His Apostles some of them wrote books and epistles that wound up being authorized as Christian Scripture, there are many other books of the New Testament that were not authored by Apostles, but that the Apostles nonetheless approved of as the pure truth.
The Apostles also spoke. They preached to the faithful, and they particularly instructed bishops, men who held the authentic Church pastorates, tasked with teaching and with celebrating Mass /sacraments. The bishops, we know from the Bible, were instructed not only in doctrine, but also in the further instruction of new bishops, so that the office of Bishop might always be held by men who were also instructed in doctrine and in the instruction of new bishops.
And the Trinity and other authentic Christian teachings /beliefs were revealed in their entirety by bishops throughout the centuries following the Events in Judaea in and around AD 33. It is in the Christian creeds and authorized /authoritative catechisms that we find the kind of "clear cut" instruction that parallel's "Hear O Israel," and, "I am Yahweh your God." And given the authorized story of the Church, teachings like the Trinity have the very same weight as do all the Christian scriptures, since they all are authenticated by Apostolic teaching authority.
In one critical way, all Christians who receive the New Testament as Scripture, also submit to 'Apostolic succession,' whether or not they admit it, because it is the Apostolic teaching authority handed on through the succession of bishops that authorized /approved the New Testament as we all know it today. By comparison, if we were to only include books and epistles actually authored by Apostles as Christian Scripture, we would exclude the Gospels of Mark and Luke, the book of Acts, the epistle of James, and possibly Jude and Revelation also, since the Apostolic authorship of these books are disputed.
