Parashas Vaeira
וַיִּקְרָא֙ גַּם־פַּרְעֹ֔ה לַֽחֲכָמִ֖ים וְלַֽמְכַשְּׁפִ֑ים וַיַּֽעֲשׂ֨וּ גַם־הֵ֜ם חַרְטֻמֵּ֥י מִצְרַ֛יִם בְּלַהֲטֵיהֶ֖ם כֵּֽן׃
Then Pharaoh, for his part, summoned the sages and the sorcerers; and the Egyptian priestly magicians, in turn, did the same with their spells:
Torah Temimah points to R’ Chiyya bar Abba — Sanhedrin 67b (verified).
בלהטיהם — א״ר חייא בר אבא: בלטיהם אלו מעשה שדים, בלהטיהם אלו מעשה כשפים.
English: “With their flames (belahateihem)” — R’ Chiyya bar Abba said: Belateihem refers to the work of demons; belahateihem refers to the work of sorcery.
Custom
Chazal distinguish two categories of Egyptian magic from the variant spellings.