Answer

The main religious scripture read during Paryushan is the Kalpa Sutra.

It is especially read in the Śvetāmbara Jain tradition during Paryushan.

Explanation

The Kalpa Sutra mainly contains sacred accounts related to:

• The lives of the Tirthankars, especially Bhagwan Mahavir
• The lineage of Jain monks and teachers
• Rules and conduct for monks during the rainy season

Traditionally, it is commonly understood as having major sections connected with:

• Jina Charitra – lives of the Tirthankars
• Sthaviravali – lineage of Jain elders/monks
• Samachari – monastic rules and conduct

Some communities may describe or arrange its reading into four parts or divisions for practical religious study during Paryushan.

Spiritual Understanding

Reading the Kalpa Sutra during Paryushan inspires devotees to reflect on:

• The life and renunciation of Bhagwan Mahavir
• Discipline and purity of conduct
• Forgiveness, self-control, and spiritual awakening

Takeaway

The scripture you are referring to is most likely the Kalpa Sutra, the main sacred text read during Paryushan in the Śvetāmbara tradition.