en_tn_condensed/jer/09/26.md

all the desert people who cut the hair on the sides of their heads very short

"all the people who live on the edge of the wilderness". People who cut their hair short in order to honor a pagan god.

For all these nations are uncircumcised

"For the people of these nations did not enter into a covenant with Yahweh through circumcision". Foreigners being uncircumcised was a sign that they were not in Yahweh's covenant.

all the house of Israel has an uncircumcised heart

"all the people of Israel are only circumcised on the outside and have not changed their hearts". An "uncircumcised heart" represents the character of a person that does not follow Yahweh and his laws.