כָּל־אִ֣ישׁ וְאִשָּׁ֗ה אֲשֶׁ֨ר נָדַ֣ב לִבָּם֮ אֹתָם֒ לְהָבִיא֙ לְכָל־הַמְּלָאכָ֔ה אֲשֶׁ֨ר צִוָּ֧ה יְהוָ֛ה לַעֲשׂ֖וֹת בְּיַד־מֹשֶׁ֑ה הֵבִ֧יאוּ בְנֵי־יִשְׂרָאֵ֛ל נְדָבָ֖ה לַיהוָֽה׃ (פ)
The children of Israel brought a freewill-offering unto the LORD; every man and woman, whose heart made them willing to bring for all the work, which the LORD had commanded by the hand of Moses to be made.
Read kabbalistic (mystical) interpretation of Exodus 35:29: and classical mystical sources.