In the chandas (Vedas), the luṅ (Aorist), laṅ (Imperfect Tense) and liṭ (Perfect Tense) are optionally used in all tenses, in relation to verbs.,
The words धातुसम्बन्ध and अन्यतरस्याम् are understood here also. By saying 'optionally', other tense-affixes may be similarly employed.
Thus देवो देवेभिरागमत् (Rig. I. I. 5.) 'O God Agni! come hither with the gods'. Here the Aorist आगमत् has the force of the Imperative. ये भूतस्य प्रचेतस इदं तेभ्योऽकरं नमः 'I make salutation &c. &c'. (Rig. X. 85. 17). Here अकरं is Aorist (लुङ्) and has the sense of the Present.
So also अग्निमद्य होतारमवृणीतायं यजमानः। Here लङ् is used instead of लट् ।
So also अद्या ममार = अद्य म्रियते । Here लिट् is used instead of लट् ।,