What are the implicatins of "Vayikach Romach be'Yado"?
Sanhedrin, 82a: It implies that he took the sword only agfter leaving the Beis-Hamidrash 1 - to teach us that it is forbidden to enter the Beis-Hamidrash wih a weapon. 2
Refer to 25:7:2:1.
See Torah Temimah, note 18, who explains the proof differently.