In The Life of Muhammad being A. Guillaume's translation of Sirat Rasul Allah by Ibn Hisham, on page 438 we read:
Supposedly `Amr intended to or suggested to kill Muhammad, but the only evidence for this allegation is that Muhammad had a revelation about this. He is killed not based on facts that he tried to kill Muhammad, but based only on Muhammad's suspicion.
`Amr b. Jihash did not receive a fair trial, somebody send a killer.
Muhammad and his enemies
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