“has laid the foundation of the earth.” Isaiah 48:13 refers to Yahweh, and there are many scriptures that say that God, Yahweh, created the heavens and the earth (cp. Gen. 1:1; Neh. 9:6; Job 9:8; 38:1, 4-6; Ps. 24:1-2; 33:6; 102:25; Jer. 10:10-12; 27:5; 32:17; 51:15; Zech. 12:1). Also, because of the spiritual battle that was raging in Isaiah’s time over the worship of pagan gods instead of Yahweh, there is a special emphasis in Isaiah that it was Yahweh who created the heavens and the earth (cp. Isa. 37:16; 40:10-12, 22, 26, 28; 42:5; 44:24; 45:12, 18; 51:13), not the pagan gods.
There are Trinitarians who say Isaiah 48:12-16 supports the Trinity. Part of their argument is their claim that Jesus Christ made heavens and earth, but we just saw many verses that said Yahweh did that, not Jesus Christ, and furthermore, Job 9:8 and Isa. 44:24 say Yahweh did it “alone.” Furthermore, the verses that some Trinitarians use to say that it was Jesus Christ who created the heavens and the earth, such as Hebrews 1:10 or Colossians 1:16 can be understood in a non-Trinitarian way without a Trinitarian meaning, and Biblical Unitarian scholars assert those verses do not support the Trinity (see commentary on Col. 1:16 and Heb. 1:10).