Rabbi Yossi Haglili agreed with the established timeline of the first Passover: God spoke on the first of the month, the lamb was selected on the tenth, and the slaughtering occurred on the fourteenth. But he arrived at this conclusion through a different chain of reasoning.
What if someone proposed that God spoke on the tenth and both the selection and the slaughtering happened on the fourteenth? Rabbi Yossi rejected this by pointing to (Exodus 12:6): "And it shall be to you for a keeping until the fourteenth day." The word "keeping" implies a period of guarding and inspection — the lamb had to be watched for blemishes before it could be slaughtered. If you claimed both selection and slaughter happened on the same day, the fourteenth, you would completely uproot this verse from its meaning. There would be no time for "keeping."
The logic is elegant: a verse that prescribes guarding an animal "until" a specific date only makes sense if there is a gap between acquisition and slaughter. Collapse that gap, and the verse becomes nonsensical.
Rabbi Yossi's argument demonstrates a core principle of rabbinic interpretation. The rabbis did not just ask what a verse says — they asked what it requires of the surrounding narrative. A proposed reading that renders another verse meaningless cannot be correct, no matter how clever it sounds. The Torah must be read as a coherent whole, where every verse retains its purpose and no instruction becomes superfluous.