Translation of the verse 49 from Surah An-Naml : Number of verses 93 - - page 381 - Part 19.
They said: "Swear one to another by Allah that we shall make a secret night attack on him and his household, and afterwards we will surely say to his near relatives: 'We witnessed not the destruction of his household, and verily! We are telling the truth.'"
They said, "Take a mutual oath by Allah that we will kill him by night, he and his family. Then we will say to his executor, 'We did not witness the destruction of his family, and indeed, we are truthful.' "
(27:49) They said to one another, "Let us pledge on an oath by Allah that we shall attack Salih and his household by night, and then tell his guardian *63 that we were not even present at the time his family were killed: we are telling the truth." *64
*63) "The guardian": the chief of the Prophet Salih's tribe, who, according to the ancient tribal tradition and custom, could make a claim to blood vengeance. The same was the position in Makkah of the Holy Prophet's uncle, Abu Talib. The Quraish were hesitant that if they attacked and killed the Holy Prophet, Abu Talib, the chief of Bani Hashim, would come out with a claim to blood vengeance on behalf of his clan .
*64) This precisely was the kind of plot which the Makkan chiefs of the clans were devising against the Holy Prophet, and they devised the same ultimately on the occasion of migration (Hijrah) to kill him. They decided that men from all the clans would attack him in a body so that the Bani Hashim could not hold any one of the clans as responsible for the murder, and, therefore, would fmd it impossible to fight all of them at one and the same time.