Where does "nothing is impossible with God" come from?

When Gabriel tells Mary "nothing will be impossible with God," he is quoting a line that was first spoken at a tent in the Negev desert about a ninety-year-old woman's womb.

The connection is in the Greek. After God promises Sarah a son in Genesis 17, he returns to reaffirm it in Genesis 18. Sarah overhears the promise and laughs to herself. God responds with a rhetorical question: "Is anything too hard for Yahweh?" (Genesis 18:14). In the original Hebrew, the word is פָּלָא (pala) — "too wonderful, surpassing." But when the Greek translators rendered the Hebrew scriptures into the Septuagint (the version Luke was reading and quoting), they chose a stronger word: ἀδυνατέω (adunateo) — "to be impossible."

So the Greek version of Genesis 18:14 reads: "Shall a word (rhēma) be impossible (adunatos) with God?"

Now look at Gabriel's words to Mary in Luke 1:37: "For nothing (pan rhēma) will be impossible (adunatasei) with God."

Same two Greek words: impossible (adunate-) and word/thing (rhēma). Same prepositional phrase: para tō theō ("with God"). Luke converts the rhetorical question at Mamre into a direct declaration to Nazareth. He's not reaching for a vague sentiment about divine power — he is quoting a specific line, in a specific context, that was spoken over a specific barren woman. And he expects the reader to feel the weight of the echo.

The announcement to Sarah and the Annunciation to Mary are structurally the same scene:

• An impossible pregnancy announced by a divine messenger
• A disbelieving human response (Sarah laughs; Mary asks "How can this be, since I have not known a man?")
• A declaration of God's ability to do the impossible
• The human comes to acceptance

The difference is the womb. Sarah's impossibility was age — a body past the season for bearing. Mary's impossibility was virginity — a body that had never been with a man. Luke is saying: the same principle that governed Genesis 18:14 governs Luke 1:37. What God declared possible for a post-menopausal womb, he now declares possible for a virgin's womb.

Jesus uses the same vocabulary himself. When his disciples ask who can be saved, he answers: "With man this is impossible, but with God all things are possible" (Matthew 19:26). The same Greek root (adunatos/dunatos, impossible/possible), the same para ("with") construction. Mark 10:27 preserves the same saying with nearly identical words. The impossibility-principle from Sarah's tent becomes the principle Jesus applies to human salvation.

The line between Genesis 17–18 and Luke 1 runs through five hundred years of prophetic repetition too. The same Hebrew verb (pala) — "too wonderful/impossible" — reappears in Jeremiah 32:17 ("nothing is too hard for you"), Jeremiah 32:27 ("is anything too hard for me?"), and Zechariah 8:6 in the restoration oracles. The Greek translators consistently rendered it with the same root Luke quotes. What God declared possible for Sarah's barren womb, the prophets re-declared over Israel's national impossibility, and Gabriel re-declares over Mary's virgin womb.

The full study on Genesis 17:15–27 traces the complete five-link chain — Genesis 18:14 through Jeremiah and Zechariah to Luke 1:37 — and shows the Greek words side by side so you can see why this is a quotation, not just a parallel theme.

Read the full study on Genesis 17:15–27