Malbim: I prepared the external (physical) needs of the building - gold, silver and craftsmen. However, Kedushah needs also Nedavah of the heart - "me'Es Kol Ish Asher Yidvenu Libo Tikchu Es Terumasi" (Shemos 25:2).

'Rashi': They are artisans.

'Rashi': Who will volunteer to bring gold, silver and everything needed for the building? This is like "Kol Nediv Lev Hevi'u" (Shemos 35:22).

Malbim: Refer to 29:5:4:2.

'Rashi': This is like "u'Mileisa Yad Aharon v'Yad Banav" (Shemos 29:9). The Targum of that verse is 'you will offer the Korban of Aharon.'

Malbim: The Nedivus (desire to give) of his heart makes him accepted in Hashem's eyes.