Tardemah is the word the Torah reaches for when a human has to be taken offstage so HaShem can act alone. The root is radam, to be in heavy sleep, and the noun form carries a weight that ordinary Hebrew words for sleep (shenah, yashen) do not. Tardemah is not rest. It is not dreaming. It is a stupor imposed from the outside, usually by HaShem Himself, and it reliably signals that the next thing in the text is an act that only one party can perform.

The two Torah occurrences frame each other. In Genesis 2:21, HaShem brings tardemah on the man so He can form the woman from his side. The man does not participate; he wakes to find her already given. In Genesis 15:12, HaShem brings tardemah on Abram at the covenant cutting. Abram does not walk between the halves of the split animals. Only YHWH does, in the form of a smoking firepot and a torch of fire, taking both sides of the covenant oath alone. The tardemah in Genesis 15 is not a footnote. It is the reason the covenant in Genesis 15 reads the way the rest of Scripture has to read it: one walker, one oath, one death owed.

The KJV renders tardemah as "deep sleep," which gets the depth but loses the agency. HALOT and BDB both mark tardemah as an imposed state, distinct from natural sleep. Job 4:13 and Job 33:15 use it for the vision-state when HaShem speaks terror into a man; Isaiah 29:10 uses it for judicial blindness poured out on the prophets. The common thread: tardemah is what happens to a human when HaShem is the only actor in the scene. When Genesis 15:12 says tardemah fell on Abram, the text is telling you in advance who will and will not be walking.