Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: The Prophet (peace and blessings be upon him) said to Sayyidah Khadijah (may Allah be pleased with her): I saw a light and I heard a voice, and I fear that I may be afflicted with madness. Sayyidah Khadijah (may Allah be pleased with her) said: Allah Almighty would not do that to you, O son of Sayyiduna Abdullah! Then Sayyidah Khadijah (may Allah be pleased with her) went to Waraqah bin Nawfal and mentioned this to him. Waraqah said: If he is telling the truth, then this is the same Namus (that is, the angel), like the Namus who came to Sayyiduna Musa (peace be upon him). If he is sent (that is, the Prophet (peace and blessings be upon him)) while I am alive at that time, I will strongly support him and help him, and I will believe in him.
Imam Ahmad recorded it both muttasil (connected) and mursal, and al-Tabarani recorded something similar, adding the words: "I will assist him." Imam Ahmad's narrators are the narrators of the Sahih.