In the chandas (Vedas) the finals of tisṛ and catasṛ are found in both ways, before the Genitive 6th-Case plural nām,
In some places they are seen as lengthened, in others not. As तिसृण मध्यंदिने or तिसॄणाम मध्यंदिने ॥ So also चतसृणाम् and चतसॄणाम् ॥,