# in the fire of my zeal
"because of my intense jealousy" or "because of my very strong anger". Yahweh loves Israel very much, so he becomes jealous and angry when other nations mock it.
# against Edom and all
"and against all of Edom"
# had both joy in their heart and contempt in their spirit, as they seized my land
"who despised the people of Israel and rejoiced while they took my land"