In Genesis 12:3, God tells Abraham:
וַאֲבָֽרְכָה֙ מְבָ֣רְכֶ֔יךָ וּמְקַלֶּלְךָ֖ אָאֹ֑ר וְנִבְרְכ֣וּ בְךָ֔ כֹּ֖ל מִשְׁפְּחֹ֥ת הָאֲדָמָֽה׃ -- And I will bless those who bless you, and the one who curses you I will curse. And all the families of the earth will bless themselves by you.
This implies that everybody will love Abraham. Who is it, then, that will curse him?
Many Rishonim observe a nuanced distinction in the text. They highlight that "וּמְקַלֶּלְךָ֖" is expressed in the singular form, whereas "מְבָ֣רְכֶ֔יךָ" is written in the plural. From this grammatical distinction, they draw an interpretation that those who curse Avraham are relatively few, while those who bless him are numerous. In the Targum Yonason's interpretation, the verse is taken quite literally, suggesting that only one individual, Bilam, will be the one to curse Avraham. (see Baal Hatorim that explains: ומקללך אאור – בגימטריא זה בלעם הבא לקלל בניך.) Rabeinu Bichayeh, on the other hand, identifies this individual as Nimrod.
However, it doesn't seem like everyone liked Avraham at the time of this blessing, especially since we know that he was thrown into a furnace of fire. (see Rabeinu Bichayeh)
