Muhammad bin 'Isa bin Hyan محمد بن عيسى بن حيان · Commercial Transactions (Kitab Al-Buyu)

I heard Messenger of Allah (ﷺ) say: But between them are certain doubtful things which many people do not recognize. He who guards against doubtful things keeps his religion and his honor blameless, but he who falls into doubtful things falls into what is unlawful.

"He said: If these classes differ, sell as you wish if payment is made on the spot."

Habal al-habalah means that a she-camel delivers an offspring and then the offspring which it delivers becomes pregnant.