Exodus 7:11

בלהטיהם The Targum renders this by בלחשיהון: with their secret spells. There is no other example of this word in the Bible. One may compare it to the first word in (Genesis 3:24) “the להט of the sword that turned round” — it appeared to turn round through some magic spell.

וַיִּקְרָא֙ גַּם־פַּרְעֹ֔ה לַֽחֲכָמִ֖ים וְלַֽמְכַשְּׁפִ֑ים וַיַּֽעֲשׂ֨וּ גַם־הֵ֜ם חַרְטֻמֵּ֥י מִצְרַ֛יִם בְּלַהֲטֵיהֶ֖ם כֵּֽן׃

Then Par῾o also called the wise men and the sorcerers: and the magicians of Miżrayim, they also did in like manner with their secret arts.