Valmiki Ramayana Kishkindha Kanda Sarga 27 Shloka 32

तत्समुत्थेन rising, शोकेन by grief, बाष्पोपहतचेतसम् mind befogged with tears, निशासु nights, शयनम् while lying in bed, गतम् gone, तम् he, निद्रा sleep, न आविवेश did not take hold him, निशासु during nights.

As Rama lay in bed, at night, his grief rose and choked him with tears.