Jamieson, Fausset and Brown on Daniel 2:30

30. not ... for any wisdom that I have--not on account of any previous wisdom which I may have manifested (Da 1:17, 20). The specially-favored servants of God in all ages disclaim merit in themselves and ascribe all to the grace and power of God (Ge 41:16; Ac 3:12). The "as for me," disclaiming extraordinary merit, contrasts elegantly with "as for thee," whereby Daniel courteously, but without flattery, implies, that God honored Nebuchadnezzar, as His vicegerent over the world kingdoms, with a revelation on the subject uppermost in his thoughts, the ultimate destinies of those kingdoms.

for their sakes that shall make known, &c.--a Chaldee idiom for, "to the intent that the interpretation may be made known to the king."

the thoughts of thy heart--thy subject of thought before falling asleep. Or, perhaps the probation of Nebuchadnezzar's character through this revelation may be the meaning intended (compare 2Ch 32:31; Lu 2:35).