Who Initiated Praying Together Together?

Was it Father Patrick Peyton the evangelistic priest who popularized the motto: “Families that Pray Together, Stay Together” in the 1950’s?
Was it the founders of PTST, who initiated “The Prayer Challenge” in their book “Couples Who Pray”?
No…

… the idea of two people being richly blessed when they pray together comes from Jesus. These are his very words:

“If two of you on earth agree about anything you pray for, it will be done for you by My Father.” Matt 18:19

“Where two or three are gathered together, in My name, I am there in the midst of them.” Matt 18:20

“Whatever you ask for in prayer, believe that you have received it, and it will be yours.” Mark 11:24