Exodus 19:3-6 (ESV)
3 while Moses went up to God. The Lord called to him out of the mountain, saying, “Thus you shall say to the house of Jacob, and tell the people of Israel:
4 ‘You yourselves have seen what I did to the Egyptians, and how I bore you on eagles' wings and brought you to myself.
5 Now therefore, if you will indeed obey my voice and keep my covenant, you shall be my treasured possession among all peoples, for all the earth is mine;
6 and you shall be to me a kingdom of priests and a holy nation.’ These are the words that you shall speak to the people of Israel.”

Exodus 20 18-21 (ESV)
18 Now when all the people saw the thunder and the flashes of lightning and the sound of the trumpet and the mountain smoking, the people were afraid and trembled, and they stood far off
19 and said to Moses, “You speak to us, and we will listen; but do not let God speak to us, lest we die.”
20 Moses said to the people, “Do not fear, for God has come to test you, that the fear of him may be before you, that you may not sin.”
21 The people stood far off, while Moses drew near to the thick darkness where God was.

Jeremiah 2:13 (ESV)
13 for my people have committed two evils: they have forsaken me, the fountain of living waters, and hewed out cisterns for themselves, broken cisterns that can hold no water.