It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) took hold of both doorposts while we were inside the house, and said: "O Banu Abd al-Muttalib, is there anyone among you who is not from you?" They said: "There is the son of one of our sisters." He (peace and blessings be upon him) said: "The son of a people's sister is one of them." Then he said: "O Banu Abd al-Muttalib, when any distress, sting (a venomous bite), hardship or adversity befalls you, say: 'Allah, Allah is our Lord; He has no partner.'"
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12733