Isaiah 50:4-5: Master Yahweh has given me the tongue of disciples, that I may know how to sustain the weary one with a word. Master Yahweh has opened my ear, and I was not disobedient nor did I turn back.
Because of her idolatries, Judah has become disabled. She cannot hear through her closed ears. She can’t sing the Lord’s praise or speak His truth. In Judah, only the Servant has an open ear and a speaking tongue, both gifts from God.
In Isaiah, the ear-tongue connection has to do with discipleship. The Servant listens to the Lord’s Word so that He can teach it with His tongue.
Tongues are for tasting as well as for speaking, and here too there is a connection between ear and tongue. Our liturgy moves from ear to tongue. We hear the Word of God, then taste His food at His table.
If you want to be nourished at this table, you have to observe that sequence: Listen before you taste. If you have closed your ears, this food will be bitter as death on your tongue. But if God has opened your ears to His voice, He gives you a tongue, so that you taste that the Lord is good.