וְכֵ֧ן תַּעֲשֶׂ֣ה לַחֲמֹר֗וֹ וְכֵ֣ן תַּעֲשֶׂה֮ לְשִׂמְלָתוֹ֒ וְכֵ֣ן תַּעֲשֶׂ֜ה לְכָל־אֲבֵדַ֥ת אָחִ֛יךָ אֲשֶׁר־תֹּאבַ֥ד מִמֶּ֖נּוּ וּמְצָאתָ֑הּ לֹ֥א תוּכַ֖ל לְהִתְעַלֵּֽם׃ (ס)
Demikian pula harus kaulakukan terhadap keledainya, demikian pula harus kaulakukan terhadap pakaiannya, dan demikian pula harus kaulakukan terhadap setiap barang saudaramu yang hilang darinya dan kautemukan; engkau tidak boleh berpura-pura tidak melihatnya.
Rashi
לא תוכל להתעלם THOU MAYEST NOT HIDE THYSELF — i.e. You must not cover your eyes, pretending not to see it.
Ibn Ezra
The phrase you cannot is here to be interpreted as it is in similar instances [cf. comment on 21: 16].
Sforno
וכן תעשה לשמלתו, even though such a find is far less likely to occur, so that you might consider it as having been abandoned on purpose.