«فَحِينَ مَلَلْنَا السُّرَى وَمِلْنَا إِلَى الْكَرَى»
When we grew weary of night travel and inclined toward sleep.
Surā is travel by night; karā is sleep. Malalnā / milnā sound similar while describing the move from tiredness to seeking rest. The sound pattern strengthens rather than obscures the progression of meaning.
After prolonged wakefulness, the prospect of a lush place to stop becomes especially appealing.