digi is substituted for de (dayate) in the liṭ (Perfect Tense).,
As अव दिग्ये, अव दिग्याते, अव दिग्यिर ॥ The root देङ् 'to protect' (Bhuadi 1011) is to be taken, and not दय 'to give' (Bhuadi 510), for that root forms its Perfect by आम् (Periphrastic Perfect) as taught in (III. I. 37). The substitute दिगि debars reduplication.,