The track was given its first airing on Mary-Anne Hobbs' radio show, which can be listened to here. The track is featured at the 2:55:00 mark.

"Mercy Is" is featured on the soundtrack to new film Noah, directed by Darren Aronofsky and starring Russell Crowe in the title role. The entire soundtrack is scored by frequent Aronofsky collaborator Clint Mansell, while Smith's entirely new contribution is the only guest appearance across the tracks.

Introducing the track, Hobbs informs that "Patti Smith asked Darren herself if she could write the lullaby that was referenced in the script and 'Mercy Is' was the result". A quote from Mansell also elaborates on the collaborative process of the track, saying "My orchestrator Matt Dunkley and I arranged the music which we roughly laid out alongside Patti's demo, and then we had Kronos and Patti play together in the studio, so it was all done in quite an old school way. This process allowed Patti and Kronos to really express themselves and really find their performance."