At this time, when no strategy had proven effective in suppressing the Deen of Islam, all the tribes of the Quraish united and wrote a resolution to boycott Muhammed (sallallahu ‘alaihi wasallam), the Banu Haashim clan and all those who supported them. The tribes of the Quraish resolved that no person would marry into the Banu Haashim nor even interact with them until they did not surrender Rasulullah (sallallahu ‘alaihi wasallam) to the Quraish so that they could kill him.

Accordingly, they wrote the details of this resolution on a piece of paper and hung it on the interior wall of the Ka‘bah. The person who wrote this document was Mansoor bin ‘Ikrimah. As soon as he wrote this oppressive and malicious document, Allah Ta‘ala punished him by causing his fingers to become paralyzed. As a result, he could never write again for the rest of his life.

Under these circumstances, Abu Taalib was forced to take his family and seek refuge in the Valley of Abu Taalib. The members of the Banu Haashim and Banu Muttalib clans, whether Muslim or non-Muslim, all gave him their full support. The Muslims supported him on account of their deen, while the non-Muslims supported him on account of their family ties. From the Banu Haashim, it was only Abu Lahab who remained in support of the Quraish.

(Extracted from Seeratul Mustafa 1/264)