In plain words
First of all, one must come to know the precious matters found in scripture through those who have experience of them. From that coming to know, an interest in them arises naturally, and then the desire to see them without fail, by whatever means, is born. This alone is called 'jñātuṃ.'
In the second stage, we investigate, look for, and gather such scriptures and special matters wherever they may be found; we see and read them directly; we inquire with great perseverance; we come to an understanding of it, and we delight in it. With that, a satisfaction arises to some extent — a contentment arises at the thought that we have come to know some precious matters. Scriptural knowledge is gained. Such a stage is called 'draṣṭuṃ.'
But if one becomes content with these two stages above, there is no benefit — there will be none. One must enter into it, become absorbed, and attain identity with it — that is, one must become absorbed in what was known and what was seen, and experience it. If one eats a meal and then, like a sluggard, does no work at all and lies down idly, there is no benefit; far from it, it causes indigestion. Only when one takes food sufficient for each day and performs bodily labor does the food eaten digest, turn to blood, and give strength to a man. In that same way, only when one digests the matters known and seen, brings them into experience — that is, into practice — and uses them for human welfare and the nation's progress, does the knowing and seeing bear any benefit. Committing the matters found in a book to memory and delivering them in the manner of a lecture is somewhat easy. Generally, the knowledge that comes from reading books is called 'book-born knowledge'; this is very common. Therefore, what one has heard, seen and eaten must, to some extent at least, take the form of practice — it must be brought into experience. This alone is called 'praveṣṭuṃ.'