Valmiki Ramayana Bala Kanda Sarga 41 Shloka 25

श्रीमान् auspicious, महीपति: lord of earth, king Sagara, इष्टयज्ञ: had completed the performance of the sacrifice, स्वपुरम् to his own capital, आगमत् reached, राजा king, गङ्गाया: Ganga, आगमे in the matter of descent, निश्चयम् decision, नाध्यगच्छत did not arrive (at any).

The great lord of the earth (king Sagara) after performing the sacrifice reached his capital. (But) He could not devise any means to bring Ganga down to the earth.