Valmiki Ramayana Ayodhya Kanda Sarga 105 Shloka 5
Original Shlokaमहतेवाम्बुवेगेन भिन्नस्सेतुर्जलागमे। दुरावारं त्वदन्येन राज्यखण्डमिदं महत्।।2.105.5।।
1 source checked for this shloka
जलागमे during the rainy season, महता great, अम्बुवेगेन by the surge of waters, भिन्नः burst सेतुः इव like a dyke, इदम् this, महत् vast, राज्यखण्डम् kingdom, त्वदन्येन other than yourself, दुरावारम् insupportable.
Like a dyke bursts under pressure by the great surge of waters during the rainy season, this vast kingdom cannot be sustained by any one except yourself.