Dear Reb Mordechai: Could you explain the concept in Chazal of "Al Tikri.....Elah....."?

Halichos/Halachos...Gavecha/Ge'echa, etc. Vayikra/Vayikar

I assume that these drashos go all the way back to Sinai, but I am wondering whether anyone has explained the rationale, if one can use that term, of this form of drash. Lechoyra, Hash-m can give the same teaching without this form of drash, in their own, other, pasukim. What does it mean to say that certain words contain more than the simple word as we see it written: that is, that halichos is ALSO halachos in the higher worlds; that gavecha is also ge'echa, etc. And if so, why those words in those pesukim.

I don't know if I explained my question clearly, but I hope you know what I mean....Thanks and a chag kosher vesameach.

David Goldman