Parashas Shemos
וַיְהִ֥י בַדֶּ֖רֶךְ בַּמָּל֑וֹן וַיִּפְגְּשֵׁ֣הוּ יְהֹוָ֔ה וַיְבַקֵּ֖שׁ הֲמִיתֽוֹ׃
At a night encampment on the way, GODhGOD This label may refer to an angel, as acting on God’s behalf. So Rashbam, Ibn Ezra; cf. Septuagint, Targum. encountered him and sought to kill him.
Torah Temimah points to Rabban Shimon ben Gamliel — Nedarim 32a (verified).
ויבקש המיתו — אמר רבן שמעון בן גמליאל: לא למשה רבינו בקש שטן להרוג אלא לאותו תינוק.
English: “And sought to kill him” — Rabban Shimon ben Gamliel said: It was not Moshe our teacher whom the adversary sought to kill, but that infant.
Custom
Chazal identify the intended victim as the infant who still required circumcision.