Parshas Hazinu:
The gematria of the Passuk: Ki lo davar reik hu mekem(for it is not a empty matter for you,rather it is your life…) = to the word Gematriot.(Rabbi Munk on Aleph Bais,Tosefes Berachah)
There is also a great vort from Pninim Meshulchan HaGra on Passuk 32:39