Hawzah News Agency – Imam al-Rida (AS) when asked about the limits of humbleness said,

أن تُعطِيَ النّاسَ مِن نَفسِكَ ما تُحِبُّ أن يُعطوكَ مِثلَهُ.

'To treat the people in the same manner you like them to treat you.'

Source: Uyun Akhbar al-Rida (AS), v. 2, p,50 no. 192