Note yajňa is not a mere ritual. It is a symbol of intense spiritual practice, both at an individual level and also at the collective level. At the end, the sage declares ‘ we have become immortal’. The verse SYV (9.21) is given below.
May life prosper by sacrifice.
May life-breath prosper by sacrifice.
May the eye prosper by sacrifice.
May the ear prosper by sacrifice.
May the back prosper by sacrifice.
May sacrifice prosper by sacrifice.
We have become the children of the Lord of life (Prajāpati).
devās!
we have attained heaven, we have become immortal. SYV (9.21)