Both of these refer to the people of Israel. (See: [[rc://en/ta/man/translate/figs-doublet]] and [[rc://en/ta/man/translate/figs-metonymy]])
# I am the first, I also am the last
This phrase emphasizes Yahweh's eternal nature. Possible meanings are 1) "I am the one who began all things, and I am the one who ends all things" or 2) "I am the one who has always lived, and I am the one who always will live." See how you translated a similar phrase in [Isaiah 44:6](../44/06.md). (See: [[rc://en/ta/man/translate/figs-merism]])
# my hand laid the foundation of the earth, and my right hand spread out the heavens
Here "hand" refers to Yahweh. AT: "I laid the foundation of the earth, and I spread out the heavens" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
The word "foundation" normally refers to a stone structure that gives support to a building from underneath. Here it describes a similar structure that was thought to support and hold the earth in place. See how you translated this in [Isaiah 24:18](../24/17.md).
Yahweh speaks of creating the heavens as if they were fabric which Yahweh stretched out. See how you translated a similar phrase in [Isaiah 42:5](../42/05.md). (See: [[rc://en/ta/man/translate/figs-metaphor]])
Standing up when Yahweh calls is a metaphor for being ready to obey him. Yahweh speaks of the earth and the heavens as if they were able to hear him and obey him. (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-personification]])