Exodus 5:3

And they said, The God of the Hebrews hath met with us, He had disclosed, revealed Himself to them in glory, He, the ancient God of the free Hebrews. Let us go, we pray thee, three days' journey into the desert, and sacrifice unto the Lord, our God, lest He fall upon us with pestilence or with the sword. The plea was that Jehovah would look upon their neglect to bring Him sacrifices as a deliberate act of disobedience, and would therefore come upon them, as their enemy, with severe punishments. Thus both ideas are brought out, that Jehovah was a jealous, and that He was a powerful God.