I will come up ... - Better; If I were to go up for one moment in the midst of thee, I should consume thee.
That I may know ... - By that sign of their repentance Yahweh would decide in what way they were to be punished.
Related Commentaries of Exodus 33:5
Exodus 33:5
5 For the LORD had said unto Moses, Say unto the children of Israel, Ye are a stiffnecked people: I will come up into the midst of thee in a moment, and consume thee: therefore now put off thy ornaments from thee, that I may know what to do unto thee.