The affix laṭ (Present Tense) comes after a root with the force of futurity when it has in construction with it the particles yāvat and purā,
The present tense has the force of the future when the adverbs यावत् and तावत् are used. The phrase 'futurity &c' is to be read into this sutra from the last. Thus आलोके ते निपतति पुरा 'he will surely fall in the range of your sight'. यावदस्य दुरात्मनः समुन्मूलनाय शत्रुघ्नं प्रेषयामि. 'I shall send Satrughna to exterminate this wretch'.
These words पुरा and यावत् must be used as adverbs (nipatas), and not as relative pronouns. Therefore not here, यावद् दास्यति तावद् भोक्ष्यते 'as long as he will give, so long he will eat'; पुरा ब्रजिष्यति 'he goes along the city'. Here यावत् is a relative pronoun; and पुरा is the Instrumental singular of पुर् 'city'.,