Because translators don’t randomly sample the space of possible translations. If the Hebrew for “lest he take and eat” is ambiguous between that and “lest he continue to take and eat”, without a clear grammatical indication it makes sense to choose the less marked form.
The fact is, even the English is more ambiguous than @Faizal_Ali is suggesting. His assertion,
just isn’t grammatically required. Such aspectual markers would make it less ambiguous, but “I ate cereal for breakfast” can be a valid alternative to “I used to eat cereal for breakfast”, with the habitual aspect left implicit from the context of the utterance, rather than explicitly marked.