'Dew' in the Bible

“O mountains of Gilboa,Let not dew or rain be upon you, nor fields with offerings;For there the shield of the mighty was defiled,The shield of Saul, [dry, cracked] not anointed with oil.

So shall we come upon David in one of the places where he can be found, and we will fall on him as the dew falls [unseen and unheard] on the ground; and of him and of all the men who are with him, not even one will be left.