וַיֵּ֗לֶךְ וַֽיַּעֲבֹד֙ אֱלֹהִ֣ים אֲחֵרִ֔ים וַיִּשְׁתַּ֖חוּ לָהֶ֑ם וְלַשֶּׁ֣מֶשׁ א֣וֹ לַיָּרֵ֗חַ א֛וֹ לְכׇל־צְבָ֥א הַשָּׁמַ֖יִם אֲשֶׁ֥ר לֹא־צִוִּֽיתִי׃
turning to the worship of other gods and bowing down to them, to the sun or the moon or any of the heavenly host, something I never commanded—
Torah Temimah points to Sanhedrin 60b.
העובד עבודת כוכבים, אחד העובד ואחד משתחוה חייב, דכתיב וילך ויעבוד אלהים אחרים וישתחו להם וכתיב בתריה וסקלתם באבנים ומתו.
English: One who serves idolatry — whether by the ordinary mode of service or by bowing — is liable, for it is written “and he went and served other gods and bowed down to them,” and after it is written “you shall stone them with stones and they shall die.”
The verse demonstrates that bowing itself is a capital form of idolatry even when it is not the customary service of that particular idol.
Derash on the verse (Bavli sugya) — not a formal named middah of the 13. The juxtaposition of service and bowing with the death penalty teaches that both acts are independently capital.
Bowing to an idol is a capital offense even if bowing is not the normal mode of worship for that idol.