Halakhah sur La Genèse 49:5

The Ramban derives support for his opinion from the fact that Yaakov strongly criticized Shimon and Levi’s actions (Bereishit 34:30). The Rambam could counter that the Torah (ibid. 31) records the retort of Shimon and Levi to this criticism, to which Yaakov does not respond. On the other hand, the Ramban could reply that Yaakov further criticized Shimon and Levi on his deathbed (Bereishit 49:5-7). Thus, the Torah gives the last word to Yaakov.