they said ask your lord to make it clear to us what sort of heifer she should be. he answered god says she should be neither too old nor too young but in between so do as you are commanded.
قالوا ادع لنا ربك يبين لنا ما هي قال إنه يقول إنها بقرة لا فارض ولا بكر عوان بين ذلك فافعلوا ما تؤمرون