Malbim Ayelet HaShachar Klal 330
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
אבל כשאומר "אמור ואמרת" הוא כפל לשון ויש בו דרוש (ויקרא ס' ג). ולחז"ל יציין הלכה למשה מסיני שאין לו יסוד בהכתוב (אמור ס' ג').
Ayelet Hashachar, translated by Betzalel Avraham Feinstein, 2021
But when it says אמור ואמרת, it is repeated language, and there will be a homiletical interpretation. And according to the sages of blessed memory, it indicates a law that was taught to Moses at Mount Sinai with no foundation in the Written Law.