«فَتَخَيَّرْنَاهَا مُنَاخًا لِلْعِيسِ وَمَحَطًّا لِلتَّعْرِيسِ»
We chose it as a place to settle the camels and halt for rest.
Munākh is a place for making camels kneel; ʿīs denotes camels. Maḥaṭṭ is a stopping place; taʿrīs refers to a journey's rest halt.
The two linked expressions attend to both the animals and the travellers. Takhayyarnāhā shows deliberate choice: they selected a suitable location after noticing its advantages.