“The LORD did not set His love on you nor choose you because you were more in number than any of the peoples, for you are the fewest of all peoples…” (Deuteronomy 7:7)
The word “fewest” or least (me'at, or LXX, oligos) is used for inconsequential (Gen 30:15), opposite of many (here, Num 13:18, etc.).
But:
"Your fathers went down to Egypt seventy persons in all, and now the LORD your God has made you as numerous as the stars of heaven.” (Deuteronomy 10:22)
How can both be true, to be the least but yet numerous as the stars? Rashi says that its that we act like we are the fewest. Other commentators say it is relative to other major peoples in the area, Egyptians, Assyrians, etc.
Notice in Deuteronomy 7:6 (as in 10:22) he is speaking to a 2nd person singular. I believe there HaShem is speaking to the people as a whole nation, one which is set apart as His people. In Deuteronomy 7:7-8 it switches to second person plural. This raises the possibility that He’s speaking to a different group—particularly, the remnant within the nation. Though we are many, it is the remnant of Israel who are few. And it is for the sake of the remnant that the nation is redeemed from Egypt.
Isaiah cries out concerning Israel: "Though the number of the Israelites is like the sand by the sea, only the remnant will be saved. For the Lord will carry out his sentence on earth with speed and finality." It is just as Isaiah said previously: "Unless the Lord Almighty had left us descendants, we would have become like Sodom, we would have been like Gomorrah." (Romans 9:27-29)
Now the remnant is the hope of the nation, the guarantee that one day all Israel will be saved, when they too believe in Yeshua.
Though there were many others, it was the few that was saved with Noah, 1 Peter 3:20. Only the few will enter into life.
Matthew 7:14 "For the gate is small and the way is narrow that leads to life, and there are few who find it.
Luke 13:23 And someone said to Him, "Lord, are there just a few who are being saved?" And He said to them, 24 "Strive to enter through the narrow door; for many, I tell you, will seek to enter and will not be able."
Revelation 3:4 “But you have a few people in Sardis who have not soiled their garments; and they will walk with Me in white, for they are worthy.”
Luke 12:32 "Do not be afraid, little flock, for your Father has chosen gladly to give you the kingdom.”
As a remnant, we would not exist or be sustained but by His grace (Rom 11:5).
For the sake of this world, the universe is secure; for the sake of Israel, the nations are secure; for the sake of the remnant, Israel is secure; it is for the sake of Messiah that the remnant is secure.