Even a child is known by his doings,.... As well as a man; "ye shall know them by their fruits", Mt 7:16; professors and profane. So a child soon discovers its genius by its actions; it soon shows its inclination and disposition; and some shrewd guesses may be made how it will turn out, a wise man or a fool, a virtuous or a vicious man; though this does not always hold good, yet something may be observed, which may be a direction to parents in the education of their children, and placing them out to what is proper and suitable for them.
Some observe, that the word has a quite contrary meaning, that "a child carries himself a stranger by his doings" ; so that he is not known by them: he so conceals and disguises himself, he acts so fraudulently and deceitfully, and plays the hypocrite, and puts the cheat on men, that they cannot tell what he is, nor what he will be; and if children can thus dissemble, as not to be known by their actions, then much more grown persons;whether his work [be] pure, and whether [it be] right; not what his present work is, or actions are, but what his later life and conversation will be; which in some measure may be judged of, though not with certainty and exactness; see Pr 22:6; especially when he acts a covert and deceitful part.
rknty "ignotus erit", i.e. "non facile cognoscitur", Vatablus; so R. Joseph Kimchi; "simulat se alium esse", Gussetius, p. 413.