Midrash su Levitico 25:13

acquire from the hand of your fellow, you shall not wrong, one man, his brother.") Whence is it derived that when you sell, you shall sell only to your fellow (Jew) (i.e., giving him first choice)? From "And if you sell a selling to your fellow." And whence is it derived that when you buy, you shall buy only from your fellow? From "or acquire from the hand of your fellow." This tells me only of land, of which Scripture is speaking (viz. Devarim 15:13). Whence do I derive (the same ["your fellow"] for) a movable object? From (the superfluous) "a selling" — to include a movable object. Whence is it derived that (the law of) ona'ah ("wronging") does not apply to land? From "or acquire from the hand … you shall not wrong" — ona'ah applies to a movable object, (which is transferred from hand to hand), but not to land.

2) And whence is it derived that ona'ah does not apply to bondsmen? From (Devarim 15:46) "And you shall hold them (bondsmen) for your sons after you as an inheritance of holding" — Just as ona'ah does not apply to a "holding" (land), so, it does not apply to bondsmen.

3) Whence is it derived that ona'ah does not apply to sacred property (hekdesh)? From ("you shall not wrong, one man,) his brother" (and not hekdesh). Whence is it derived that ona'ah does not apply to writs (of indebtedness)? From "selling," connoting something whose substance is bought and sold — to exclude writs, whose substance is not bought and sold, but which only serve as corroboration thereof — wherefore ona'ah does apply to writs which are sold as (wrapping) for spices.