Matthew Poole and continuators on Job 39:2

2. Canst thou number the months that they fulfil? or knowest thou the time when they bring forth ?

Dost thou exactly know when they did conceive, and when they will bring forth: which is more uncertain in these than in other Creatures, because there fall out many accidents which cause them to bring forth before their time, as thunder, Psal. 29. 9. and other like causes of sudden fear which may be many and various in those desert places where they live.