Nedeh (H5078) refers to a gift or payment — with particular emphasis in Ezekiel on the improper 'gifts' given to hired prostitutes as a metaphor for Israel's idolatrous payments to foreign powers (Ezek 16:33-34). Unlike the generous nedavah (freewill offering), nedeh carries a connotation of transactional exchange that corrupts relationship. Ezekiel uses it to expose the absurdity of Israel's spiritual adultery: unlike ordinary harlots who receive payment, Israel paid others to come worship their idols.
The contrast between nedeh and the freewill offering (nedavah, H5071) is theologically significant. True worship gives freely and receives freely — grace operating in both directions. But idolatry inverts this: it costs you everything and gives you nothing of lasting value. Jesus contrasted true worship (in spirit and truth, John 4:24) with the transactional religiosity that had corrupted the temple (Mark 11:15-17). The gifts we bring to God should flow from love, not from the manipulation of nedeh.