The word "their" refers to the past generations of Israel who had rebelled against God. The word "children" refers to current generation of people living in Israel.
## stubborn faces and hard hearts ##
These two descriptions are both used to describe the people of Israel not wanting to change how they live in order to obey God. (See: [[rc://en/ta/man/translate/figs-doublet]])
## they have stubborn faces ##
"the expression on their faces shows that they are stubborn" or "they are stubborn" (See: [[rc://en/ta/man/translate/figs-metonymy]])
## stubborn ##
"unwilling to change"
## hard hearts ##
This phrase suggests the people's resistance to God and their unwillingness to obey him. The heart is used to describe the place in the body where a person decides what they want to do. (See: [[rc://en/ta/man/translate/figs-metaphor]])