Prayer on behalf of another person or group of people; it has a long history in the Bible, from Abraham pleading for Sodom (Gen. 18: 22–33), Moses on behalf of the enslaved Israelites (Exod. 5: 22–3), the prophets (Amos 7: 1–6), and also for the people. In the NT Jesus interceded for Peter (Luke 22: 32) and Paul for the Ephesians (Eph. 1: 17).
The epistle of James urges intercession for the sick (Jas. 5: 13–17). Such intercession has continued down the ages. Its rationale has been questioned (is it an intention to try to change the will of God?) but justified as ‘making possible for God to do something which he could not have done without our asking’.