7537. 'And Jehovah said to Moses' means further instruction about what had to be done, see above in 7517.

7517. 'And Jehovah said to Moses and to Aaron' means fresh instruction. This is clear from the meaning of 'Jehovah said' as instruction, as above in 7497. The instruction is fresh because a new state is dealt with now, the previous one having come to an end. Instruction given by Jehovah comes through the truth that emanates from Him; and truth that emanates from Jehovah is represented by 'Moses and Aaron', inward truth by 'Moses' and outward truth by 'Aaron', 7382.