God: "I looked for someone to take a stand for me, and stand in the gap" (Ezekiel 22:30)
All tongues are for the sake of unbelievers [1 Cor. 14:22]. In other words, that gift has no purpose in the church when everyone present is a believer. And once the sign served its purpose to pronounce judgment or cursing on Israel, and the judgment fell, the purpose ceased along with the sign gift. The blessing of that sign was that God would build a new nation of Jews and Gentiles to be His people (Gal. 3:28), to make Israel jealous and someday repent (Rom. 11:11, 12, 25-27). The sign was thus repeated when Gentiles were included in the church (Ac. 10:44-46).
Now what is food for the inner man? Not prayer, but the Word of God; and here again, not the simple reading of the Word of God, so that it only passes through our minds, just as water passes through a pipe, but considering what we read, pondering it over and applying it to our hearts.