NET

31 So when the envoys arrived from the Babylonian officials to visit him and inquire about the sign that occurred in the land, God left him alone to test him, in order to know his true motives.

Darby

31 However in [the matter of] the ambassadors of the princes of Babylon, who sent to him to inquire of the wonder that was done in the land, God left him, to try him, that he might know all [that was] in his heart.

KJV

31 Howbeit in [the business of] the ambassadors of the princes of Babylon, who sent unto him to enquire of the wonder that was [done] in the land, God left him, to try him, that he might know all [that was] in his heart.