Samadhi practice is necessary after a kensho experience. With this practice you can gain full control of suppressed vexations, and disperse vexations which have already manifested. However, the samadhi you cultivate after a kensho experience is quite different from the samadhi you practice before having seen your self-nature.

Therefore, the person who has seen his self-nature still needs both precepts and samadhi. The precepts will help prevent the person from doing things that will cause more vexation, and samadhi will help to eliminate those vexations which have not yet manifested.