From chalaph; properly, exchange; hence (as preposition) instead of -- X for.
see HEBREW chalaph
H2500. cheleph
I. חֵ֫לֶף noun [masculine] exchange, only construct, as preposition in return for (so הֲלַף, , common in Aramaic e.g. Genesis 4:23 ᵑ6 ᵑ7 for Hebrew תַּחַת) — ׳ח עֲבֹדָתָם (עֲבֹדַתְכֶם) Numbers 18:21, 31 (both P).