In Jainism, "Saath lakh" (meaning "six hundred thousand") is commonly referenced in connection with the Dravyasangraha Sutra. The phrase "saath lakh" is famously found in the verse that speaks about the countless number of souls (jivas) and their forms. However, more specifically, it is most directly associated with Shri Jinasena Acharya's "Mahapurana", where the enumeration of different types of beings—specifically the "84 lakh yoni" (84 lakhs of life forms)—is mentioned.

If you are referring to its appearance in a specific Jain sutra, the concept of "saath lakh" (six lakh) is also found in the Jain "Uttaradhyayana Sutra", which mentions the number of possible rebirths or types of transmigrations experienced by souls.

To summarize:

• "Saath lakh" is a number often cited in Jain scriptures to indicate the vastness of life forms or transmigrations.
• It is referenced in texts such as the Uttaradhyayana Sutra and Mahapurana.
• In some contexts, it is also mentioned in Dravyasangraha Sutra or explanatory texts.

If you provide the full verse or context, I can identify the exact sutra and its Jain canonical source.