When the word kim or its derivatives are in construction with a verb, the affix laṭ (Present Tense) is used optionally after a root, in denoting future time, provided that the sentences expresses a desire of gaining on the part of the speaker.,
The word 'optionally' is understood in this sutra. By using the word वृत्त along with किं it is meant that the rule applies even when किम् takes the affixes डतर and डतम. The word लिप्सा means 'the desire of gaining or acquiring, a wish to have something or an intention of begging'.
As कं भवन्तो भोजयन्ति or भोजयितारः 'whom will you feed'? It implies a request on the part of the questioner to feed him also. So also कतरो भिक्षां दास्यति, ददाति, दाता, or कतमो भिक्षां दास्यति &c, 'Which of the two or which of these all, will he give alms? Will he give something to me'?
When no desire of gain is implied, the future tense must be employed as कः पाटलीपुत्रं गमिष्यति 'who will go to Pataliputra'.,