The Saum (fast) will intercede for the servant on the Day of Judgement:

'Abdullaah Ibn 'Amr [Radi Allahu anhu: May Allah be pleased with him] reported that the Messenger of Allaah [Salla Allahu Aleihi Wassalam] said: "The fast and the Qur'aan will intercede for the servant on the Day of Judgement. The fast will say: 'My Lord, I restricted him from food and drink, so allow me to intercede for him.' And the Qur'aan will say: 'I prevented him from sleeping at night, so allow me to intercede for him.' So they will be allowed to intercede." Saheeh Muslim