"Check the Pep in Your Step!"

Narrated by Abu Hurairah (RadiyaAllaahu Ta'aAla Anhu): the Prophet (SallaAllaahu Alayhi Wa Salaam) said,

"Once a man was walking along in a new set of clothes, with his hair well combed and with a 'SWAGGER' to his step, pleased with himself, Allah caused the earth to swallow him and he will keep sinking until the Day of Ressurrection."

And in another narration with slight different wording:

Abu Hurairah (RadiyaAllaahu Ta'aAla Anhu) reported Allaah's messenger (Sallallaahu Alayhi Wa Salaam) said,

"There was a person who used to walk with pride because of his thick hair and fine mantles. He was made to sink in the earth and he would go on sinking in the earth until the Last Hour."

[Saheeh Muslim]