And the Lord responds, v. 19:  "And the LORD said, "I will cause all my goodness to pass in front of you, and I will proclaim my name, the LORD, in your presence. I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion. 20 But," he said, "you cannot see my face, for no one may see me and live."

So, when the Lord shows his back to Moses, when he comes to Him and shows Him who He is, here is what he tells/shows Moses.  This is the essentialness of God:   (Ex 34)    

                      5 Then the LORD came down in the cloud and stood there with him and proclaimed his

                       name, the LORD. 6 And he passed in front of Moses, proclaiming, "The LORD, the LORD,

                        the compassionate and gracious God, slow to anger, abounding in love and faithfulness,

                        7 maintaining love to thousands, and forgiving wickedness, rebellion and sin. Yet he does

                         not leave the guilty unpunished; he punishes the children and their children for the sin of

                         the fathers to the third and fourth generation."

 8 Moses bowed to the ground at once and worshiped. 9 "O Lord, if I have found favor in your eyes," he said, "then let the Lord go with us. Although this is a stiff-necked people, forgive our wickedness and our sin, and take us as your inheritance."

Then we skip over to Numbers 14.    A few weeks or months later, Israel arrives at the edge of the Promised Land, but they refuse to go in.  By this point, God's anger is really kindled--

11 The LORD said to Moses, "How long will these people treat me with contempt? How long will they refuse to believe in me, in spite of all the miraculous signs I have performed among them? 12 I will strike them down with a plague and destroy them, but I will make you into a nation greater and stronger than they."

Moses' response was 2-fold:

1.  Lord, your honor is at stake.  Everybody knows what you did.  If you slaughter them in the desert, they will all think you couldn't fulfill your promise.   Your reputation is in danger.

but moreso, Moses takes what God told him, previously:

2.    "Now may the Lord's strength be displayed, just as you have declared:"  [you told me you were this way, Lord, now carry through]  

               18 'The LORD is slow to anger, abounding in love and forgiving sin and rebellion. Yet he does

               not leave the guilty unpunished; he punishes the children for the sin of the fathers to the third

                and fourth generation.' 19 In accordance with your great love, forgive the sin of these people,

                just as you have pardoned them from the time they left Egypt until now."

And the Lord forgives them, as Moses requests.   To be sure, there are still consequences, but God does as Moses asks. 

Moses has begged God to show him the essence of His character, and God does so:  He is compassionate, gracious, slow to anger, abounding in love and faithfulness, yet He does punish sin.

And Moses turns around and throws it back up to God, later:   God, you said you would be this way; now show this character that you proclaimed for yourself, in this situation.

There is a strong reliance on God's word, there, but none-the-less, an incredible boldness, to cast God's own words almost against Him.  Yet there's also a trust in God's character--the faith that God will back up who He has claimed to be.

Much to ponder, there--much room for my faith to grow.