The final of dā and dhā (dhu roots) may optionally be elided in the leṭ (Vedic Subjunctive).,
As दधद्रत्ना दाशुषे Rig I. 35. 8. सामो ददद् गन्धर्वाय Rig X. 85. 41. But also यदग्निरग्नये ददात् ॥ The form ददात्, however, may also be deduced even when the final of दा is elided, for then by the आट् augment 3.4.94 we get this form. The word वा is therefore employed in the sutra only for the sake of distinctness, for the sutra without वा would have also given the above forms, as we have shown. Or the वा is used to remove the doubt which one may entertain to this effect \ ददात् is the form which may be deduced by the general rule, since लोप is taught, this form will be excluded altogether and will never appear\.
The form दधत् is thus evolved. We add तिप् to the root धा; then the इ of ति is elided 3.4.97. दाशुषे = यजमानाय रत्नानि दद्यात् ॥ Others say, the दधत् is the form of the root with the शतृ affix. ददत् is from the root दाञ् ॥
Some say that वा is jnapaka and indicates the existence of the following maxim :- अनित्यमागमशासनम् \the rule about augments is anitya\. So that the augment आट् being anitya, we could not have got the form ददात् ॥ Hence the employment of the word वा ॥,