"If I saw you in Heaven" is a line from which song?

Eric Clapton composed "Tears in Heaven" after a particularly painful period in his life. During this very dark period, Clapton, within a several-month span, lost a friend/peer, his own manager, two associates, and his young son to death. Thus "Tears in Heaven" is meant to address those tragedies, specifically the loss of Conor, the singer's four-year-old son. And outside of that, the track is also intended to in some capacity fit into the general theme of the 1991 movie "Rush", since it was created specifically to be featured on that project.

Lyrically the song is relatively-terse. And the best way to describe it is the singer addressing someone in the afterlife, specifically "in heaven". First, that would imply that the individual he is speaking to was indeed a righteous person, as in someone he deems would be received favorably into the hereafter. And basically, what Eric is asking is if this individual he loved so much on the earthly plane would also remember him if they were to meet "in heaven". So ultimately, the song does not read as if Mr. Clapton is also deceased and is interacting with this person. Rather this is a theoretical inquiry he is putting forth the land of the living.