Canto 2 -
Ayodhyā-kāṇḍa
Chapter 24: Rāma Instructs Kausalyā
Text 2.24.25

व्रतोपवासनिरता या नारी परमोत्तमा।
भर्तारं नानुवर्तेत सा तु पापगतिर्भवेत्॥

vratopavāsa-niratā yā nārī paramottamā
bhartāraṁ nānuvarteta sā tu pāpa-gatir bhavet

vrata-upavāsa-niratā = busily engaged in her vows and fasts; = who; nārī = woman; parama-uttamā = most exalted in religiosity; bhartāram = her husband; na = not; anuvarteta = and who does serve; = that; tu = but; pāpa-gatiḥ = attain a result similar to the result of sinful activities; bhavet = will.

But that woman, who is most exalted in religiosity, busily engaged in her vows and fasts, and who does not serve her husband, will attain a result similar to the result of sinful activities.1

In this and the next verse, Lord Rāma indirectly and directly points out that a wife’s highest dharma is to serve her husband.

1 Because she has avoided her specific dharma—the dharma of a wife.