Yūnus ibn Bukayr transmitted from Ibn Isḥāq that Waraqah said:

[Metre: al-Ṭawīl]
If what you have told us, O Khadījah, is indeed true,
then know that Aḥmad is a Messenger;
Gabriel comes to him, and Michael beside him,
bringing down from God a revelation that opens the breast.
He who gains it through sincere repentance shall prosper,
while the captive, heedless and misled, shall be wretched.
Two parties shall there be: one in His gardens,
and another, shackled in the depths of Hellfire.
Whenever they call out for doom within it,
clubs rain upon their heads, after which the flames flare up.
Glory be to Him who drives the winds by His command,
who, throughout the days, does whatsoever He wills—
He whose Throne is above all the heavens,
whose decrees concerning His creation are never altered.

Waraqah also said:

[Metre: al-Basīṭ]
Alas for men, and for the turns of time and destiny!
Nothing God decrees can ever be averted.
Even Khadījah summons me that I might inform her
of a matter I foresee will reach people in days to come.
She told me of something I had already heard of
in ages long gone and former epochs:
that Gabriel comes to Aḥmad and tells him,
“You have been sent to all mankind.”
I said, “May the One in whom you hope bring it to pass for you;
look forward to good and wait in patience.
Send him to us, so that we may question him
about his affair—what he sees in sleep and in wakefulness.”
When he came to us, he spoke wondrous words
that made the hair and skin upon us bristle:
“I saw the Trustworthy Spirit of God confronting me
in a form perfected beyond all forms.”
He went on, and fear nearly overwhelmed me
as the trees around me greeted him with salām.
So I said—my own surmise, though I know not whether they will credit me—
that he will be sent to recite the revealed sūrahs.
And I shall tell you, should they openly oppose his summons,
of striving in God’s cause, without self-praise or rancour.

Such is how al-Ḥāfiẓ al-Bayhaqī recorded these lines in his "Dalāʾil;" yet I have reservations about their authenticity as coming from Waraqah. God knows best.