1)
What is the significance of the phrase "Ish Ish mi'Melachto ... "?
1.
Ramban (in Pasuk 3) and Seforno: To teach us at one and the same time, the integrity of the workers and the generosity of the donors. 1
1
As well as the integrity of the foreman, who immediately publicized the fact that sufficient had been donated and that they should stop donating, who, unlike others in a similar position, was not interested in making a buck or two by allowing extra money to come in (Ramban).
2)
What are the implications of the word "Ish Ish mi'Melachto ... "?
1.
Shabbos, 96b: It implies that each person was able to do his work without assistance from anybody else.