"My lord, hear me: a land worth four hundred shekels of silver" (Genesis 23:15-16). This is what the verse says: "A man with an evil eye hastens after wealth" (Proverbs 28:22), this is Ephron, who cast an evil eye upon the money of Abraham. He said: if you wish to give four hundred centenaria of silver from the merchandise of your house, you are able to give it to me. "And he does not know that want will come upon him" (Proverbs 28:22), for Scripture diminished him a letter vav, as it is said, "And Abraham weighed out to Ephron [Efron]": "Ephron" is written here defectively, lacking a vav. [Bracketed gloss: in the spelling of Ephron's name in this verse the letter vav is omitted, hinting that he was "diminished."]
Ephron's Greedy Eye and the Missing Letter in His Name
Yalkut Shimoni on Torah 102:19
(בראשית כג טו-טז) אֲדֹנִי שְׁמָעֵנִי אֶרֶץ אַרְבַּע מֵאוֹת שֶׁקֶל כֶּסֶף, זֶהוּ שֶׁאָמַר הַכָּתוּב, (משלי כח, כב) "נִבְהָל לַהוֹן אִישׁ רַע עָיִן", זֶה עֶפְרוֹן, שֶׁהִכְנִיס עַיִן הָרַע בְּמָמוֹנוֹ שֶׁל אַבְרָהָם. אָמַר אִי אַתְּ בָּעֵי לְמִתַּן אַרְבַּע מֵאָה קַנְטְרִין דְּכֶסֶף מִן סְחוֹרָתָא דְּבֵיתְךָ, אַתְּ יָכִיל יְהַב לִי "וְלֹא יֵדַע כִּי חֶסֵר יְבֹאֶנּוּ", שֶׁחִסְּרוֹ הַכָּתוּב וָי"ו שֶׁנֶּאֱמַר וַיִּשְׁקֹל אַבְרָהָם לְעֶפְרֹן, עֶפְרוֹן תָּנִינָא חָסֵר וָי"ו.