What about all the Gentiles in the OT?
In the Torah/Pentateuch we find references that include the non-Israelites.
The word "Law" has taken on a very negative persona, but I believe Doctrine, Instructions, Directions, Corrections for blessings/righteousness is the whole of the "law in the OT".
2Ti_3:16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
YHWH (The LORD) knew that the people, Israelites and non-Israelites would not be able to keep the "Law" and thus receive the blessings. The provision to bring back "all the peoples" was planned from the beginning of the story of Adam and Eve. That provision was that Immanuel (God with us) would come in the flesh, live a sinless life, die and resurrect and then return back to heaven while Jesus' disciples and the apostles spread the Good News.
Many have wondered "Why did Jesus have to die and resurrect?" And with the Spring months come the question "Was Jesus in the grave for a literal 3 days and 3 nights, and does it even matter?" What is truth and is a half-truth not a lie?
Deu 29:14 Neither with you only do I make this covenant and this oath;
Deu 29:15 But with him that standeth here with us this day before the LORD our God,
and also with him that is not here with us this day:
Exo 19:8 And all the people answered together, and said, All that the LORD hath spoken we will do. And Moses returned the words of the people unto the LORD.
Exo_12:49 One law shall be to him that is homeborn, and unto the stranger that sojourneth among you.
Num_15:16 One law and one manner shall be for you, and for the stranger that sojourneth with you.
Num_15:29 Ye shall have one law for him that sinneth through ignorance, both for him that is born among the children of Israel, and for the stranger that sojourneth among them.
So instead of "One Law" we now are "One in Christ".
Eph 2:11 Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
Eph 2:12 That at that time ye were without Christ,
being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
Eph 2:13 But now in Christ Jesus
ye who sometimes were far off are made nigh by the blood of Christ.
Eph 2:14 For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us;
Eph 2:15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
Eph 2:16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
Eph 2:17 And came and preached peace
to you which were afar off, and to them that were nigh.