It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that he said: I heard al-Hajjaj giving a sermon, and he said something that I disliked, so I remembered the saying of the Messenger of Allah (peace and blessings be upon him): "It is not fitting for a believer to humiliate himself." I said: "O Messenger of Allah! How does he humiliate himself?" He (peace and blessings be upon him) said: "He exposes himself to a trial that he does not have the strength to bear."
Imam al-Tabarani (may Allah have mercy on him) said: "Only Abd al-Karim narrated this hadith from Mujahid; Warqa' is alone in narrating it, and this hadith is not narrated from Ibn Umar (may Allah be pleased with them both) except with this chain."
Hadith Referenceالمعجم الأوسط / باب الميم / 5357
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 13507»