HH, Sir Godfrey Gregg D.Div
Both the Old and New Testaments feature multiple instances of believers practising fasting and prayer together. Here are a handful of the examples I found:
The Israelites fasted and lifted up prayers of praise and confession after sinning against God (Nehemiah 9).
Esther fasts with Israel and prays for the strength to ask her husband to spare Israel from Haman’s plot of genocide (Esther 4:16).
David mentions praying and fasting for his enemies (Psalm 35:12-14).
Daniel fasts and prays to lament Israel’s disobedience while exiled in Babylon and asks God to have mercy on His chosen people (Daniel 9).
The prophet Anna fasted and prayed regularly for Israel, then prophesied to Mary and Joseph about Jesus (Luke 2:36-38).
Paul and Barnabas pray and fast to ask for guidance in appointing elders over the first-century church (Acts 14:23).