Here "heart" refers to Pharaoh. His stubborn attitude is spoken of as if his heart was hard. See how you translated this phrase in [Exodus 9:12](../09/11.md). AT: "caused Pharaoh to became more defiant" (See: [[rc://en/ta/man/translate/figs-synecdoche]] and [[rc://en/ta/man/translate/figs-metaphor]])
# he would not let them go
"Pharaoh would not let them go"
# Be careful about one thing
"Make sure of one thing" or "Be certain of one thing"
# you see my face
Here the word "face" refers to the whole person. AT: "you see me" (See: [[rc://en/ta/man/translate/figs-synecdoche]])