Valmiki Ramayana Sundara Kanda Sarga 56 Shloka 16

मेघपादनिभैः appearing like the feet of clouds, पादैः with its feet, सर्वत: all over, प्रक्रान्तमिव as if traversing, अभ्रमालिभिः with ranges of clouds, शिखरैः with its peaks, आकाशे in the sky, जृम्भमाणमिव as if yawning.

With the ranges of foothills appearing like the feet of clouds traversing, with its peaks like garlands of clouds traversing over the mountain, it made one feel it was yawning.