It is a line from Barah Bhavna (Barah Bhavna Stuti), a well-known Jain meditation with 12 bhavnas (reflections). The verse you quoted is the opening stanza of that set.

Original text (opening stanza, in Roman script as found in many recensions): Raja Rana chhatra-pati, hathin ke as-var, Mar-na sab ko ek din, apni-apni bar.

Meaning (arth) in Jain tradition:

• It uses monarchal imagery to symbolize the impermanence and fragility of worldly power.
• The verse calls to reflect on death and the eventual dissolution of all beings, reminding the practitioner to renounce ego, wealth, and possessions.
• The overall aim is to cultivate detachment, compassion, and detachment from violence and attachment, so one can progress toward spiritual awakening.

Notes:

• Barah Bhavna as a whole is the practice of twelve specific inner bhavnas, taught to purify the mind and aid spiritual progress.
• There are minor textual variations between Digambar and Shwetambar recensions in some editions, but the core theme of renunciation, non-violence, and reverence for the Jain path remains consistent.

If you’d like, I can summarize all twelve bhavnas or provide the rest of the Barah Bhavna verses in a simple, student-friendly format.