Sa'id al-Khudri narrated it from his father
I went to Quba' with the Messenger of Allah (ﷺ) on Monday till we reached (the habitation) of Banu Salim. The Messenger of Allah (ﷺ) stood at the door of 'Itban and called him loudly. So he came out dragging his lower garnment. Upon this the Messenger of Allah (ﷺ) said: We have made this man to make haste 'Itban said: Messenger of Allah, if a man parts with his wife suddenly without seminal emission, what is he required to do (with regard to bath)? The Messenger of Allah (ﷺ) said: It is with the seminal emission that bath becomes obligatory.