Adam Clarke on Daniel 1:4

Children - ילדים yeladim, youths, young men; and so the word should be rendered throughout this book.

Skilled in all wisdom - Rather, persons capable of every kind of literary accomplishment, that they might be put under proper instruction. And as children of the blood and of the nobles mere most likely, from the care usually taken of their initiatory education, to profit most by the elaborate instruction here designed, the master of the eunuchs, the king's chamberlain, was commanded to choose the youths in question out of such.