Sheet music is available here: https://www.sheetmusicplus.com/title/21991565
This piano medley of two beloved hymns begins with a simple rendition of How Firm a Foundation. The Rock of Ages is presented with the left hand taking the melody. Finally, the piece concludes with Rock of Ages played in right hand chords while How Firm a Foundation is played simultaneously in the left. It's like these two hymns were made for each other!
Our foundation is His Word, our refuge is Christ. But God's truth stands firm like a foundation stone with this inscription: 'The Lord knows those who are his...2 Timothy 2:19a.