What did God do in the hearts of those who came to do the work?
God put wisdom and understanding in the hearts of the wisehearted workers, and He stirred their hearts to come to the work. He gave them the ability to perform every task for the sanctuary service, so both their skill and their willingness to serve came from Him.
Les explains from Exodus 36:1-2 that Bezalel, Aholiab, and every wisehearted man received wisdom and understanding from the Lord to know how to work all manner of work for the service of the sanctuary. Moses called those whose heart the Lord had put wisdom and whose heart stirred him up to come to the work. Les stresses that God is the One who gives ability, and whatever we are or hope to be is because of what God has done in and through us. Every believer has a role and a gift, and God gave gifted people to bring about His work. It had to start with the heart.
And Moses called Bezaleel and Aholiab, and every wise hearted man, in whose heart the LORD had put wisdom, even every one whose heart stirred him up to come unto the work to do it: