Al-Adab Al-Mufrad #480

Hanash ibn al-Harith reported that his father said, "One of our men had a mare which became pregnant which he then slaughtered, saying, 'Will I live long enough to ride this horse?' Then we received 'Umar's letter telling us to attend to the provision that Allah has given us in order to make it thrive since there is still time in the business."