वृद्धकुमारी - an old virgin, वाक्य means utterance. This Nyaya has become on the basis of the utterance of some virgin who has become old. There is a story - A virgin who has grown old is asked to ask for only one boon. After good thinking she asks - my sons eat rice with ghee and milk in golden utensils. Thus the old virgin asked for a husband and sons, along with that she asked for ghee, milk other eatables and gold which means riches. This Nyaya is conceived on the basis of the old virgins utterance.
This Nyaya can give much inspiration and advice in various contexts of human life. Here we think about the advice in the context of food. We know that many kinds of vitamins, minerals proteins etc. are desired for good health. To acquire all those as much needed we have to eat different vegetables and grains. But as time comes when a person has to acquire all these by eating only one eatable, he must drink cow-milk. According to what that old virgin said we get all the necessary elements from cow-milk.
When time somebody acquires many things through only one undertaking. The achievement of the man can be expressed by using this Nyaya sentence.