Midrasz do Rodzaju 33:11

What is meant by the plague was stayed? R. Isaac declared that this means that he grasped the angel and restrained him. Therefore, when Moses was about to depart from this world, he said: Bless, Lord, his substance, and accept the work of his hands; smite through the loins of them that rise up (Deut. 33:11). Bless, Lord, his substance, that is, may his strength be blessed. Accept the work of his hands alludes to the incense through which he atoned, as it is said: And he put on the incense, and made atonement (Num. 17:12). Smite through the loins of them that rise up indicates that he smote the angel and restrained him.