Sahih Muslim
The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wal-Adab)
Book Number: 032 / Hadith Number: 6351
Abu Huraira reported Allah's Messenger (may peace he upon him) as saying: Many a person with disheveled hair and covered with dust is turned away from the doors (whereas he is held in such a high esteem by Allah) that if he were to adjure in the name of Allah (about anything) Allah would fulfil that.