One of the most overt references to the divine identity of Jesus in the Gospel of Matthew is the fact that his name is “Emmanuel,” God with us. Christ’s “with-ness” is reinforced at the end of the Gospel when He tells His disciples: “Lo I am with you always to the very end of the age.” This “Emmanuel” language, I would argue, has significant roots in the OT and identifies Jesus with the God of Abraham, Isaac, and Jacob. A brief search for the phrase “I am with you” in the OT produced the following results:
(Gen 26:24 ESV) And the LORD appeared to him the same night and said, “I am the God of Abraham your father. Fear not, for I am with you and will bless you and multiply your offspring for my servant Abraham’s sake.”
(Gen 28:15 ESV) Behold, I am with you and will keep you wherever you go, and will bring you back to this land. For I will not leave you until I have done what I have promised you.”
(Isa 41:10 ESV) fear not, for I am with you; be not dismayed, for I am your God; I will strengthen you, I will help you, I will uphold you with my righteous right hand.
(Isa 43:5 ESV) Fear not, for I am with you; I will bring your offspring from the east, and from the west I will gather you.
(Jer 1:8 ESV) Do not be afraid of them, for I am with you to deliver you, declares the LORD.”
(Jer 1:19 ESV) They will fight against you, but they shall not prevail against you, for I am with you, declares the LORD, to deliver you.”
(Jer 15:20 ESV) And I will make you to this people a fortified wall of bronze; they will fight against you, but they shall not prevail over you, for I am with you to save you and deliver you, declares the LORD.
(Jer 30:11 ESV) For I am with you to save you, declares the LORD; I will make a full end of all the nations among whom I scattered you, but of you I will not make a full end. I will discipline you in just measure, and I will by no means leave you unpunished.
(Jer 42:11 ESV) Do not fear the king of Babylon, of whom you are afraid. Do not fear him, declares the LORD, for I am with you, to save you and to deliver you from his hand.
(Jer 46:28 ESV) Fear not, O Jacob my servant, declares the LORD, for I am with you. I will make a full end of all the nations to which I have driven you, but of you I will not make a full end. I will discipline you in just measure, and I will by no means leave you unpunished.”
(Hag 1:13 ESV) Then Haggai, the messenger of the LORD, spoke to the people with the LORD’s message, “I am with you, declares the LORD.”
(Hag 2:4 ESV) Yet now be strong, O Zerubbabel, declares the LORD. Be strong, O Joshua, son of Jehozadak, the high priest. Be strong, all you people of the land, declares the LORD. Work, for I am with you, declares the LORD of hosts,
(Mat 28:20 ESV) And behold, I am with you always, to the end of the age.”
Notice especially the similarity between Matthew 28:20 and Gen. 28:15. I don’t have my LXX handy to do a comparison of the Greek (if anyone knows of an online LXX let me know), but I would almost bet that the similarities are there in the Greek too. Surely it is no coincidence that Jesus speaks like YHWH when He says: “Lo, I am with you…”