R. Shimon b. Yochai says: Now if of those of whom "quickly" (i.e., "and you will go lost quickly") was written, were exiled only after the passage of much time (i.e., even though they were idolatrous for many years, they were not exiled until the days of Tzidkiyahu), how much more so (will this [long passage of time] obtain with) those (Gog, etc.), of whom "quickly" was not written, it being written (of them, Ezekiel 38:8) "After many years you will be remembered (for punishment)."
"and you will go lost quickly … (18) And you shall place these, My words, upon your heart": Even though I am exiling you from Eretz Yisrael, be observant of the mitzvoth, so that when you return they will not be new to you. An analogy: A king was angry with his wife and she returned to her father's house. The king: "Continue wearing your jewels, so that when you return, they will not be new to you." So, the Holy One Blessed be He to Israel (in exile): "My children, be observant of the mitzvoth, so that when you return, they will not be new to you." As Jeremiah said (to the Jews going into exile, Jeremiah 31:21) "Set up signposts (tziyunim) for yourselves": These are the mitzvoth, in which Israel are distinctive (metzuyanim). (Ibid.) "Make high heaps for yourself": reminiscent of the destruction of the Temple, viz. (Psalms 137:5) "If I forget you, O Jerusalem, let my right hand be forgotten." (Jeremiah, Ibid.) "Set your heart to the road, the way on which you came.": The Holy One Blessed be He says to them: "My children, give heart to the ways in which you walked, and repent (of them), and immediately you will return to your cities, viz. (Ibid.) "Repent, O virgin of Israel — Return to these, your cities!"