en_tn_condensed/isa/30/12.md

you reject this word

"you reject this message"

trust in oppression and deceit and lean on it

Possible meanings are 1) the leaders of Judah are trusting in the Egyptian leaders who rule by oppressing and deceiving others or 2) the leaders of Judah have oppressed and deceived their own people in order to take their money and send it to the Egyptians leaders as payment for protection.

lean on

This means to trust or rely on something.