Hawzah News Agency – Imam al-Rida (AS) when asked by Ibn al-Jahm, 'What are the limits of humbleness that makes a servant humble when he observes them?' to which he (AS) replied,

التَّواضُعُ دَرَجاتٌ: مِنها أن يَعرِفَ المَرءُ قَدرَ نَفسِهِ فيُنزِلَها مَنزِلَتَها بقَلبٍ سَليمٍ، لا يُحِبُّ أن يأتيَ إلى‏ أحَدٍ إلّا مِثلَ ما يُؤتى‏ إلَيهِ؛ إن رأى‏ سَيّئةً دَرأها بِالحسَنَةِ، كاظِمُ الغَيظِ، عافٍ عَنِ النّاسِ، واللَّهُ يُحِبُّ المُحسِنينَ.

'Humbleness has stages; that one knows the value of his self and places it in its right position with a sincere heart, that he likes to treat people the same way he expects them to treat him, that he responds the wrong with good, that he controls his anger and forgives the people. And Allah likes the good doers.'

Source: Al-Kafi, v. 2, p. 124, no. 13