Arcana Coelestia # 9858
9858. 'With the work of a designer' means a product of the understanding. This is clear from the meaning of 'a designer' as the power of understanding, dealt with in 9598, 9688. The words 'a product of the understanding' are used because the Lord's spiritual kingdom, which is represented by Aaron's garments, is heaven's power of understanding, even as His celestial kingdom is its power of will. And the powers of understanding and will that a human being has correspond to those heavens, see 9835.
John 15:26-27
26
"When the Counselor has come, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, he will testify about me.
27
You will also testify, because you have been with me from the beginning.