John 1:36

and looking upon Jesus walking about, says, Behold, the Lamb of God.

John 1:29

On the following day he sees Jesus coming to him, and says, Behold the Lamb of God, that taketh away the sin of the world.

Hebrews 12:2

looking unto Jesus the beginner and perfecter of our faith; who for the joy that was placed before him, endured the cross, looking with contempt at the shame, and has sat down on the right hand of the throne of God.

1 Peter 1:19-20

but by the precious blood of Christ, as a lamb without blemish and spotless:

Treasury of Scripture Knowledge

Summary

And looking upon Jesus as he walked, he saith, Behold the Lamb of God!

Bible References

Behold

John 1:29
On the following day he sees Jesus coming to him, and says, Behold the Lamb of God, that taketh away the sin of the world.
Hebrews 12:2
looking unto Jesus the beginner and perfecter of our faith; who for the joy that was placed before him, endured the cross, looking with contempt at the shame, and has sat down on the right hand of the throne of God.
1 Peter 1:19
but by the precious blood of Christ, as a lamb without blemish and spotless: