dhi is substituted for the Imperative affix hi in the chandas (Vedas) after 1. śru 2. śṛṇu 3. pṝ 4. kṛ and 5. vṛ,
As श्रुधी हविमिन्द्र, शृणुधी, गिरः, पूर्धि, उरुकृदुरुणस्कृ and अवावृधि, ॥
In शृणुधी, the हि is not elided after the उ of णु as it was required by 6.4.106, since the present aphorism specifically mentions it. The lengthening takes place by 6.3.137. The forms other than शृणुधि are irregular; शप् being added diversely by 3.1.85, and then elided diversely by बहुलं छन्दसि 2.4.73,