मम मातुर्महद्दुःखमतुलं शुभलक्षण।
अभिप्रायमविज्ञाय सत्यस्य च शमस्य च॥
mama mātur mahad duḥkham atulaṁ śubha-lakṣaṇa
abhiprāyam avijñāya satyasya ca śamasya ca
mama = My; mātuḥ = mother’s; mahat = is great; duḥkham = distress; atulam = and unparalleled; śubha-lakṣaṇa = O one of auspicious characteristics; abhiprāyam = the confidential mystery; avijñāya = because she does not understand; satyasya ca = of the dharma of truthfulness; śamasya = mental equilibrium; ca = and.
O one of auspicious characteristics, My mother’s distress is great and unparalleled because she does not understand the confidential mystery of the dharma of truthfulness and mental equilibrium.1
1 Śamasya indicates that Kausalyā didn’t understand the mystery of spiritual life. See Śrīmad-Bhāgavatam 11.19.36. One who progresses in spiritual life gives up adharma and accepts those elements of dharma that are favorable for spiritual progress in the mode of goodness. In other words, he is not a materialistic follower of Vedic dharma. He is a spiritual follower of Vedic dharma. Rāma demonstrates this.
Lord Rāma intends to ask Lakṣmaṇa, “Why do You speak what You spoke when You do understand the confidential mystery concerning dharma?”
He then explains the nature of dharma as follows.