Cattāri Brahmavihārā

Verse 184. Patience Is A Great Ascetic Virtue

Patience’s the austerity supreme,
Nibbana’s supreme the Buddhas say.
One who irks or others harms
is not ordained or monk become.

Explanation: Enduring patience is the highest asceticism. The Buddhas say that imperturbability (Nibbana) is the most supreme. One is not a renunciate if he hurts another. Only one who does not harm others is a true saint (samana)

And an inspiring Dhamma talk by Ajahn Pasanno on patience: http://mirror1.birken.ca/dhamma_talks/indiv/Pas/06/27_-_Patience_and_Steadfastness.mp3

Source: http://www.buddhanet.net/dhammapada/d_buddha.htm