(Leviticus 5:21-22) What does Scripture teach by saying 'his neighbor,' 'his neighbor,' two times? 'His neighbor' excludes that which belongs to the Most High [consecrated property]; 'his neighbor' excludes that which belongs to others. 'And deals falsely' - one might think this includes one who says to his fellow, 'I ate today,' when he did not eat, or 'I went to such-and-such a city,' when he did not go; therefore Scripture says, 'if he sins' (Leviticus 5:21) [implying a wrong involving money, not mere talk]. 'And deals falsely' - I have spoken only of a denial preceded by a sin [an actual wrong], excluding a denial not preceded by a sin. Rabbi says: What does Scripture teach by saying, 'and deals falsely with his neighbor regarding a deposit, or a pledge, or a robbery, or has oppressed his neighbor, or has found a lost object' (Leviticus 5:21-22)? Just as these are distinctive in being matters of money, so are excluded those that are not matters of money.
Why Scripture Says His Neighbor Twice About a False Denial
Yalkut Shimoni on Torah 479:6
(ויקרא ה כא-כב) מַה תַּלְמוּד לוֹמַר עֲמִיתוֹ עֲמִיתוֹ שְׁנֵי פְּעָמִים, עֲמִיתוֹ פְּרָט לְגָבוֹהַּ, עֲמִיתוֹ פְּרָט לַאֲחֵרִים. וְכִחֵשׁ, יָכוֹל הָאוֹמֵר לַחֲבֵרוֹ אָכַלְתִּי הַיּוֹם וְהוּא לֹא אָכַל, הָלַכְתִּי לְעִיר פְּלוֹנִי וְהוּא לֹא הָלַךְ, תַּלְמוּד לוֹמַר "כִּי תֶחֱטָא". וְכִחֵשׁ, לֹא אָמַרְתִּי אֶלָּא בְּכַחַשׁ שֶׁקְּדָמוֹ חֵטְא, יָצָא כַּחַשׁ שֶׁלֹּא קְדָמוֹ חֵטְא. רַבִּי אוֹמֵר, מַה תַּלְמוּד לוֹמַר "וְכִחֵשׁ בַּעֲמִיתוֹ בְּפִקָּדוֹן אוֹ בִתְשׂוּמֶת יָד אוֹ בְגָזֵל אוֹ עָשַׁק אֶת עֲמִיתוֹ, אוֹ מָצָא אֲבֵדָה", מָה אֵלּוּ מְיֻחָדִין שֶׁהֵן שֶׁל מָמוֹן יָצְאוּ אֵלּוּ שֶׁאֵינָן שֶׁל מָמוֹן.