Dragon Ball Z - episode 38 - 27 Feb, 1990

Because the ship works on voice commands given in the Namekian language, Mr. Popo teaches Bulma a little of the language so she can operate the spaceship. Meanwhile, Goku, Krillin, and Gohan recover from their wounds. Because Goku's injuries are worse, he has to stay in the hospital after Gohan and Krillin are completely recovered. Gohan and Krillin decide to accompany Bulma on her journey to planet Namek. (Source: Wikipedia)